CVE-2025-4981: Path Traversal Leading to RCE by Any Authenticated Mattermost User

Severity: critical (CVSS 9.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-06-20 · updated 2026-06-17
Weakness: CWE-427

Description

Mattermost versions 10.5.x <= 10.5.5, 9.11.x <= 9.11.15, 10.8.x <= 10.8.0, 10.7.x <= 10.7.2, 10.6.x <= 10.6.5 fail to sanitize filenames in the archive extractor which allows authenticated users to write files to arbitrary locations on the filesystem via uploading archives with path traversal sequences in filenames, potentially leading to remote code execution. The vulnerability impacts instances where file uploads and document search by content is enabled (FileSettings.EnableFileAttachments = true and FileSettings.ExtractContent = true). These configuration settings are enabled by default.

Affected products

Mattermost: from 9.11.0 before 9.11.16; from 10.5.0 before 10.5.6; from 10.6.0 before 10.6.6; from 10.7.0 before 10.7.3; 10.8.0, 10.8.0-rc1, 10.8.0-rc2, 10.8.0-rc3 — fixed in 10.5.6, 10.6.6, 10.7.3, 9.11.16

How to fix

Upgrade to a fixed version: Mattermost 10.5.6, 10.6.6, 10.7.3, 9.11.16. Check the vendor advisory for mitigations.

References

https://mattermost.com/security-updates

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