Mattermost

Mattermost versions 11.3.0 and earlier, 11.2.2 and earlier, and 10.11.10 and earlier contain an array length handling vulnerability in the calls plugin that allows unauthenticated remote attackers to trigger out-of-memory (OOM) errors and crash the server by sending maliciously crafted msgpack frames over websocket connections. With a CVSS score of 5.8 and network-based attack vector requiring no privileges or user interaction, this denial-of-service vulnerability poses a moderate but easily exploitable availability risk to any exposed Mattermost deployment.

Mattermost versions 11.3.0 and 11.2.2 and earlier fail to properly validate the run_create permission when a playbook ID is empty, allowing authenticated team members to create unauthorized playbook runs through the API. This permission bypass could enable attackers with valid credentials to perform actions they should not be permitted to execute within the platform.

Mattermost versions 11.3.0, 11.2.2, and 10.11.10 and earlier lack proper memory bounds checking when processing DOC file uploads, enabling authenticated attackers to trigger server memory exhaustion and denial of service. An attacker with valid credentials can upload a specially crafted DOC file to exhaust available memory and crash the Mattermost server. This vulnerability currently lacks a patch and affects multiple active versions of the platform.

This vulnerability in Mattermost allows guest users to bypass team-specific file upload permissions through a cross-team file metadata reuse attack. Affected versions include Mattermost 11.3.0, 11.2.x up to 11.2.2, and 10.11.x up to 10.11.10. An authenticated guest user can upload a file in a team where they have upload_file permission, then reuse that file's metadata in POST requests to channels in different teams where they lack upload permission, resulting in unauthorized file posting with potential integrity impact.

Mattermost fails to properly validate User-Agent header tokens in versions 11.3.0 and earlier, 11.2.2 and earlier, and 10.11.10 and earlier, allowing authenticated attackers to trigger request panics through specially crafted User-Agent headers. This denial-of-service vulnerability affects availability but requires prior authentication and results in only low-severity impact. While the CVSS score of 4.3 reflects the low severity, the practical risk depends on whether the application is exposed to untrusted authenticated users and whether automatic exploitation tools are readily available.

Mattermost 10.11.x through 11.3.x fails to validate password length, allowing unauthenticated attackers to trigger denial of service by submitting multi-megabyte passwords during login attempts that consume excessive CPU and memory resources. The vulnerability affects all versions up to 10.11.10, 11.2.2, and 11.3.0, with no patch currently available.

This vulnerability in Mattermost allows unauthenticated attackers to achieve remote code execution and exfiltrate sensitive credentials through malicious plugin installation on CI test instances that retain default admin credentials. Affected versions include Mattermost 10.11.x through 10.11.10, 11.2.x through 11.2.2, and 11.3.0, with the core issue stemming from insufficient access controls on plugin installation combined with default credential exposure. An attacker can upload a malicious plugin after modifying the import directory to gain full system compromise and access AWS and SMTP credentials stored in configuration files.

Mattermost versions 11.3.x up to and including 11.3.0 contain an information disclosure vulnerability where burn-on-read posts fail to maintain their redacted state when deleted, allowing authenticated channel members to view previously hidden message contents through WebSocket post deletion events. The vulnerability requires low-privilege authenticated access and results in confidentiality loss of sensitive communications that were intentionally designed to be self-destructing. With a CVSS score of 4.3 and network-based attack vector, this represents a meaningful but contained risk primarily affecting organizations relying on Mattermost's burn-on-read feature for secure internal communications.

Mattermost fails to properly bound memory allocation when processing PSD (Photoshop) image files, allowing authenticated attackers to exhaust server memory and trigger denial of service by uploading a specially crafted PSD file. The vulnerability affects Mattermost versions 11.3.0 and earlier, 11.2.2 and earlier, and 10.11.10 and earlier. With a CVSS score of 4.3 and a low attack complexity requirement, this represents a moderate but exploitable risk for organizations running affected versions where user file upload is permitted.

This vulnerability is an improper access control flaw in Mattermost's channel search functionality that allows removed team members to enumerate all public channels within private teams. Affected versions include Mattermost 11.3.x through 11.3.0, 11.2.x through 11.2.2, and 10.11.x through 10.11.10. An authenticated attacker who has been removed from a team can query the channel search API endpoint to discover the complete list of public channels in that private team, resulting in information disclosure without requiring elevated privileges.

Mattermost fails to properly sanitize client-supplied post metadata in its post update API endpoint, allowing authenticated attackers to spoof permalink embeds and impersonate other users through crafted PUT requests. The vulnerability affects Mattermost versions 11.3.0 and earlier, 11.2.2 and earlier, and 10.11.10 and earlier. While the CVSS score of 4.3 is moderate and requires authentication, the integrity impact allows attackers to deceive users by falsely attributing messages to legitimate users, potentially facilitating social engineering or misinformation campaigns within Mattermost instances.

Mattermost fails to properly validate user permissions when filtering invite IDs during team creation, allowing authenticated users to bypass access controls and register unauthorized accounts using leaked or discovered invite tokens. Affected versions include Mattermost 11.3.0 and earlier in the 11.3.x branch, 11.2.2 and earlier in the 11.2.x branch, and 10.11.10 and earlier in the 10.11.x branch. An authenticated attacker with knowledge of valid invite IDs can circumvent intended access restrictions to create accounts that should be restricted, resulting in unauthorized account registration and potential lateral movement within the Mattermost instance.

Mattermost fails to enforce response size limits on integration action endpoints, allowing an authenticated attacker to trigger server memory exhaustion and denial of service by clicking an interactive message button that connects to a malicious integration server returning arbitrarily large responses. This vulnerability affects Mattermost versions 11.3.0, 11.2.x up to 11.2.2, and 10.11.x up to 10.11.10. While the CVSS score of 5.3 is moderate, the attack requires user interaction (UI:R) and network access, but can be reliably triggered by any authenticated user interacting with crafted messages.

Mattermost Android Mobile Apps versions <=2.21.0 fail to properly configure file providers which allows an attacker with local access to access files via file provider. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.

Mattermost versions 10.1.x <= 10.1.2, 10.0.x <= 10.0.2, 9.11.x <= 9.11.4, 9.5.x <= 9.5.12 fail to limit the file size for slack import file uploads which allows a user to cause a DoS via zip bomb by. Rated medium severity (CVSS 4.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 10.1.x <= 10.1.2, 10.0.x <= 10.0.2, 9.11.x <= 9.11.4, 9.5.x <= 9.5.12 fail to properly validate the type of callProps which allows a user to cause a client side (webapp and. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 10.1.x <= 10.1.2, 10.0.x <= 10.0.2, 9.11.x <= 9.11.4, and 9.5.x <= 9.5.12 fail to prevent concurrently checking and updating the failed login attempts. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

Mattermost versions 9.7.x <= 9.7.5, 9.8.x <= 9.8.2 and 9.9.x <= 9.9.2 fail to properly propagate permission scheme updates across cluster nodes which allows a user to keep old permissions, even if. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 10.0.x <= 10.0.1, 10.1.x <= 10.1.1, 9.11.x <= 9.11.3, 9.5.x <= 9.5.11 fail to properly validate email addresses which allows an unauthenticated user to bypass email domain. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost versions 10.0.x <= 10.0.0 and 9.11.x <= 9.11.2 fail to properly query ElasticSearch when searching for the channel name in channel switcher which allows an attacker to get private channels. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.10.x <= 9.10.2, 9.11.x <= 9.11.1, 9.5.x <= 9.5.9 and 10.0.x <= 10.0.0 fail to properly authorize the requests to /api/v4/channels which allows a User or System Manager, with. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.11.x <= 9.11.2, and 9.5.x <= 9.5.10 fail to protect the mfa code against replay attacks, which allows an attacker to reuse the MFA code within ~30 seconds. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

Mattermost versions 9.10.x <= 9.10.2, 9.11.x <= 9.11.1 and 9.5.x <= 9.5.9 fail to prevent detailed error messages from being displayed in Playbooks which allows an attacker to generate a large. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost versions 9.10.x <= 9.10.2, 9.11.x <= 9.11.1, 9.5.x <= 9.5.9 fail to sanitize user inputs in the frontend that are used for redirection which allows for a one-click client-side path. Rated medium severity (CVSS 4.6), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.10.x <= 9.10.2, 9.11.x <= 9.11.1, 9.5.x <= 9.5.9 fail to check that the origin of the message in an integration action matches with the original post metadata which allows an. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.9 fail to properly filter the channel data when ElasticSearch is enabled which allows a user to get private channel names by using cmd+K/ctrl+K. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.11.X <= 9.11.1, 9.5.x <= 9.5.9 icorrectly issues two sessions when using desktop SSO - one in the browser and one in desktop with incorrect settings. Rated low severity (CVSS 3.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.10.x <= 9.10.1, 9.9.x <= 9.9.2, 9.5.x <= 9.5.8 fail to limit access to channels files that have not been linked to a post which allows an attacker to view them in channels that. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.8 fail to properly authorize access to archived channels when viewing archived channels is disabled, which allows an attacker to view posts and files of archived. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.11.x <= 9.11.0 and 9.5.x <= 9.5.8 fail to validate that the message of the permalink post is a string, which allows an attacker to send a non-string value as the message of a. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.8 fail to include the metadata endpoints of Oracle Cloud and Alibaba in the SSRF denylist, which allows an attacker to possibly cause an SSRF if Mattermost was. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.11.x <= 9.11.0, 9.10.x <= 9.10.1, 9.9.x <= 9.9.2 and 9.5.x <= 9.5.8 fail to properly authorize requests when viewing archived channels is disabled, which allows an attacker to. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost Desktop App versions <=5.8.0 fail to sufficiently configure Electron Fuses which allows an attacker to gather Chromium cookies or abuse other misconfigurations via remote/local access. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost Desktop App versions <=5.8.0 fail to safeguard screen capture functionality which allows an attacker to silently capture high-quality screenshots via JavaScript APIs. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost Mobile Apps versions <=2.18.0 fail to disable autocomplete during login while typing the password and visible password is selected, which allows the password to get saved in the dictionary. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost Desktop App versions <=5.8.0 fail to specify an absolute path when searching the cmd.exe file, which allows a local attacker who is able to put an cmd.exe file in the Downloads folder of a. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.0, 9.8.x <= 9.8.2 fail to enforce permissions which allows a guest user with read access to upload files to a channel. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0, 9.8.x <= 9.8.2 fail to properly enforce permissions which allows a user with systems manager role with read-only access to teams. Rated medium severity (CVSS 4.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 fail to properly enforce permissions which allows a team admin user without "Add Team Members" permission to disable the invite URL. Rated low severity (CVSS 2.7), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 and 9.8.x <= 9.8.2 fail to restrict which roles can promote a user as system admin which allows a System Role with edit access to. Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 fail to enforce proper access controls which allows any authenticated user, including guests, to mark any channel inside any team as read for any. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0, 9.8.x <= 9.8.2 fail to restrict the input in POST /api/v4/users which allows a user to manipulate the creation date in POST. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0, 9.8.x <= 9.8.2 fail to sanitize user inputs in the frontend that are used for redirection which allows for a one-click. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 and 9.8.x <= 9.8.2 fail to ensure that remote/synthetic users cannot create sessions or reset passwords, which allows the munged. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.7 and 9.10.x <= 9.10.0 fail to time limit and size limit the CA path file in the ElasticSearch configuration which allows a System Role with access to the. Rated medium severity (CVSS 4.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0, 9.8.x <= 9.8.2, when shared channels are enabled, fail to redact remote users' original email addresses stored in user props when. Rated low severity (CVSS 3.7), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.0 and 9.5.x <= 9.5.6 fail to validate the source of sync messages and only allow the correct remote IDs, which allows a malicious remote to set arbitrary RemoteId. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5 and 9.8.x <= 9.8.1 fail to disallow the modification of local channels by a remote, when shared channels are enabled, which allows a. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5, 9.8.x <= 9.8.1 fail to properly validate synced posts, when shared channels are enabled, which allows a malicious remote to. Rated high severity (CVSS 7.1), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5, 9.8.x <= 9.8.1 fail to disallow users to set their own remote username, when shared channels were enabled, which allows a user on a. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6 fail to properly restrict channel creation which allows a malicious remote to create arbitrary channels, when shared channels were enabled. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5, 9.8.x <= 9.8.1 fail to properly safeguard an error handling which allows a malicious remote to permanently delete local data by. Rated high severity (CVSS 8.7), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5 and 9.8.x <= 9.8.1 fail to disallow unsolicited invites to expose access to local channels, when shared channels are enabled, which. Rated critical severity (CVSS 9.6), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5 and 9.8.x <= 9.8.1 fail to properly validate that the channel that comes from the sync message is a shared channel, when shared. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5, 9.8.x <= 9.8.1 fail to disallow the modification of local users when syncing users in shared channels. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6 fail to properly validate synced reactions, when shared channels are enabled, which allows a malicious remote to create arbitrary reactions on. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost Mobile Apps versions <=2.16.0 fail to validate that the push notifications received for a server actually came from this serve that which allows a malicious server to send push. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost Mobile Apps versions <=2.16.0 fail to protect against abuse of a globally shared MathJax state which allows an attacker to change the contents of a LateX post, by creating another post. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost versions 9.8.0, 9.7.x <= 9.7.4, 9.6.x <= 9.6.2, 9.5.x <= 9.5.5 fail to prevent specifying a RemoteId when creating a new user which allows an attacker to specify both a remoteId and the. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost versions 9.8.x <= 9.8.0, 9.7.x <= 9.7.4, 9.6.x <= 9.6.2 and 9.5.x <= 9.5.5, when shared channels are enabled, fail to use constant time comparison for remote cluster tokens which allows an. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.5 and 9.8.0 fail to properly sanitize the recipients of a webhook event which allows an attacker monitoring webhook events to retrieve the channel IDs of archived or. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost versions 9.8.0, 9.7.x <= 9.7.4, 9.6.x <= 9.6.2 and 9.5.x <= 9.5.5 fail to prevent users from specifying a RemoteId for their posts which allows an attacker to specify both a remoteId and. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.5 and 9.8.0 fail to sanitize the RemoteClusterFrame payloads before audit logging them which allows a high privileged attacker with access to the audit logs to read. Rated low severity (CVSS 2.7), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.5 and 9.8.0, when using shared channels with multiple remote servers connected, fail to check that the remote server A requesting the server B to update the profile. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost Desktop App versions <=5.7.0 fail to correctly prompt for permission when opening external URLs which allows a remote attacker to force a victim over the Internet to run arbitrary programs. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost Desktop App versions <=5.7.0 fail to disable certain Electron debug flags which allows for bypassing TCC restrictions on macOS. Rated low severity (CVSS 3.3), this vulnerability is low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.3, 9.6.x <= 9.6.1, 8.1.x <= 8.1.12 fail to restrict the audience of the "custom_playbooks_playbook_run_updated" webhook event, which allows a guest on a channel with. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.3, 9.7.x <= 9.7.1, 9.6.x <= 9.6.1 and 8.1.x <= 8.1.12 fail to check if the email signup configuration option is enabled when a user requests to switch from SAML to. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.3, 9.6.x <= 9.6.1 and 8.1.x <= 8.1.12 fail to perform proper input validation on post actions which allows an attacker to run a playbook checklist task command as. Rated medium severity (CVSS 5.7), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.3, 9.6.x <= 9.6.1 and 8.1.x <= 8.1.12 fail to enforce proper access controls which allows user to view arbitrary post contents via the /playbook add slash command. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.3, 9.6.x <= 9.6.1 and 8.1.x <= 8.1.12 fail to perform proper access control which allows a guest to get the metadata of a public playbook run that linked to the. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.3, 9.7.x <= 9.7.1 and 8.1.x <= 8.1.12 fail to perform a proper authorization check in the /api/v4/groups/<group-id>/channels/<channel-id>/link endpoint which allows a. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.3, 9.6.x <= 9.6.1, 8.1.x <= 8.1.12 fail to enforce proper access controls for channel and team membership when linking a playbook run to a channel which allows. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.3, 9.6.x <= 9.6.1 and 8.1.x <= 8.1.12 fail to perform proper authorization checks which allows a member running a playbook in an existing channel to be promoted to a. Rated medium severity (CVSS 6.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.5.x <= 9.5.3, 9.7.x <= 9.7.1, 9.6.x <= 9.6.1, 8.1.x <= 8.1.12 fail to enforce proper access control which allows a user to run a slash command in a channel they are not a member. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.6.0, 9.5.x before 9.5.3, and 8.1.x before 8.1.12 fail to fully validate role changes which allows an attacker authenticated as team admin to demote users to guest via crafted. Rated low severity (CVSS 2.7), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.6.0, 9.5.x before 9.5.3, and 8.1.x before 8.1.12 fail to fully validate role changes, which allows an attacker authenticated as a team admin to promote guests to team admins via. Rated low severity (CVSS 2.7), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 8.1.x before 8.1.12, 9.6.x before 9.6.1, 9.5.x before 9.5.3, 9.4.x before 9.4.5 fail to limit the number of active sessions, which allows an authenticated attacker to crash the. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.6.0, 9.5.x before 9.5.3, 9.4.x before 9.4.5, and 8.1.x before 8.1.12 fail to handle JSON parsing errors in custom status values, which allows an authenticated attacker to crash. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 9.6.x <= 9.6.0, 9.5.x <= 9.5.2, 9.4.x <= 9.4.4 and 8.1.x <= 8.1.11 fail to remove detailed error messages in API requests even if the developer mode is off which allows an. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 8.1.x <= 8.1.10, 9.6.x <= 9.6.0, 9.5.x <= 9.5.2 and 8.1.x <= 8.1.11 fail to limit the size of a request path that includes user inputs which allows an attacker to cause excessive. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost Mobile app versions 2.13.0 and earlier use a regular expression with polynomial complexity to parse certain deeplinks, which allows an unauthenticated remote attacker to freeze or crash. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mattermost versions 8.1.x before 8.1.11, 9.3.x before 9.3.3, 9.4.x before 9.4.4, and 9.5.x before 9.5.2 fail to authenticate the source of certain types of post actions, allowing an authenticated. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Improper Access Control in Mattermost Server versions 9.5.x before 9.5.2, 9.4.x before 9.4.4, 9.3.x before 9.3.3, 8.1.x before 8.1.11 lacked proper access control in the `/api/v4/users/me/teams`. Rated low severity (CVSS 3.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost Server versions 9.5.x before 9.5.2, 9.4.x before 9.4.4, 9.3.x before 9.3.3, 8.1.x before 8.1.11 don't limit the number of user preferences which allows an attacker to send a large number. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Improper Access Control in Mattermost Server versions 8.1.x before 8.1.11 allows an attacker that is in a channel with an active call to keep participating in the call even if they are removed from. Rated low severity (CVSS 3.1), this vulnerability is remotely exploitable. No vendor patch available.

Mattermost versions 8.1.x before 8.1.10, 9.2.x before 9.2.6, 9.3.x before 9.3.2, and 9.4.x before 9.4.3 fail to correctly verify account ownership when switching from email to SAML authentication,. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost versions 8.1.x before 8.1.10, 9.2.x before 9.2.6, 9.3.x before 9.3.2, and 9.4.x before 9.4.3 fail to limit the number of @-mentions processed per message, allowing an authenticated. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Mattermost Jira plugin versions shipped with Mattermost versions 8.1.x before 8.1.10, 9.2.x before 9.2.6, 9.3.x before 9.3.2, and 9.4.x before 9.4.3 fail to escape user-controlled outputs when. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Resource Exhaustion in Mattermost Server versions 8.1.x before 8.1.10 fails to limit the size of the payload that can be read and parsed allowing an attacker to send a very large email payload and. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.