Severity by source
AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H
High privileges (admin with SAML write) required; network vector, no user interaction, limited integrity impact, high availability impact.
Primary rating from Vendor (Mattermost).
CVSS VectorVendor: Mattermost
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H
Lifecycle Timeline
1DescriptionCVE.org
Mattermost versions 11.8.x <= 11.8.0, 11.7.x <= 11.7.3, 11.6.x <= 11.6.5, 10.11.x <= 10.11.20 fail to verify file deletion path which allows an admin with SAML system-console write permissions to delete arbitrary files outside the config directory from the server via the remove file endpoint.. Mattermost Advisory ID: MMSA-2026-00666
AnalysisAI
Path traversal in Mattermost allows an admin user with SAML system-console write permissions to delete arbitrary files outside the intended directory, causing high availability impact. Affected versions include 10.11.x through 10.11.20, 11.6.x through 11.6.5, 11.7.x through 11.7.3, and 11.8.0. No public exploit is identified at time of analysis, but the required high privileges limit the immediate risk.
Technical ContextAI
The vulnerability is a classic path traversal (CWE-22) in the Mattermost server's remove file endpoint, which fails to properly sanitize user-supplied file paths before deletion. The affected product, identified by CPE cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*, is a self-hosted collaboration platform. The flaw lies in the backend file-handling logic that does not restrict the path within the configuration directory, allowing an attacker to escape with directory traversal sequences. The attack requires SAML system-console write permissions, a feature used for managing server configuration files in SAML-authenticated environments.
RemediationAI
The vendor advises upgrading to a patched version; exact fixed versions are not specified in the available data, so consult the official Mattermost security advisory at https://mattermost.com/security-updates for the appropriate upgrade. As an immediate workaround, restrict SAML system-console write permissions to a minimal set of trusted administrators, and monitor access to the remove file endpoint for suspicious activity. Note that the workaround does not eliminate the underlying vulnerability, so patching remains essential.
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Same weakness CWE-22 – Path Traversal
View allSame technique Path Traversal
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-49852
GHSA-rxgw-2f9c-c2hh