EUVD-2026-77374
GHSA-r9qc-jm62-qwq5
Severity by source
AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Network REST API requires low-privilege authenticated user; no confidentiality or integrity impact, only Playbooks plugin availability loss.
Primary rating from Vendor (Mattermost).
CVSS VectorVendor: Mattermost
Lifecycle Timeline
2DescriptionCVE.org
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate that a property field belongs to the specified run before updating its value which allows an authenticated user with run property-management access to crash the Playbooks plugin via a REST request referencing a property field that belongs to a different run. Mattermost Advisory ID: MMSA-2026-00684
AnalysisAI
Mattermost's Playbooks plugin can be crashed by an authenticated user via a malformed REST request that references a property field belonging to a different run than specified. Affected versions span the 10.11.x, 11.7.x, 11.8.x, and 11.9.x release branches, per vendor advisory MMSA-2026-00684. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires: (1) a valid Mattermost account with at least low-level authentication, (2) the run property-management permission within the Playbooks plugin specifically, and (3) knowledge of a property field ID belonging to a different run than the one being targeted - obtainable by any user with read access to multiple runs. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The vendor-supplied CVSS 6.5 (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) is well-calibrated for this issue. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | Upgrade Mattermost to a version beyond the affected maximums in the branch currently deployed - above 11.9.0 on the 11.9.x branch, above 11.8.4 on 11.8.x, above 11.7.7 on 11.7.x, or above 10.11.22 on 10.11.x. … Detailed patch versions, workarounds, and compensating controls in full report. |
Threat intelligence, references, and detailed analysis are available after sign-in.
More in Mattermost
View allMattermost versions 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to properly validate boa
Denial of service in linkify-it (npm) through v5.0.0 lets remote unauthenticated attackers wedge a rendering worker by s
A denial-of-service vulnerability in Mattermost allows an authenticated user to crash the server via multiple large auto
Mattermost version 7.1.x and earlier fails to sufficiently process a specifically crafted GIF file when it is uploaded w
A remote code execution vulnerability (CVSS 9.9) that allows authenticated users. Critical severity with potential for s
Mattermost versions 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to properly validate inp
Privilege escalation to full administrative control in Mattermost self-hosted server (versions 11.6.0 and earlier in the
Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to to verify that t
Mattermost versions 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12, 11.0.x <= 11.0.3 fail to properly validat
Mattermost webapp fails to validate route parameters in/<TEAM_NAME>/channels/<CHANNEL_NAME> allowing an attacker to perf
Fleet is an open source osquery manager. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable,
Mattermost versions 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to use prepared statemen
Share
External POC / Exploit Code
Leaving vuln.today