CVE-2025-4981 is a critical-severity (CVSS 9.9) CWE-427 vulnerability in github.com/mattermost/mattermost-server. A fix is available for github.com/mattermost/mattermost-server — see the affected versions and patch details below.
Path Traversal Leading to RCE by Any Authenticated Mattermost User
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-4981.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/mattermost/mattermost-server🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost-server | all versions | 0.0.0-20250519205859-65aec10162f6go get github.com/mattermost/mattermost-server@v0.0.0-20250519205859-65aec10162f6 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | all versions | 8.0.0-20250519205859-65aec10162f6go get github.com/mattermost/mattermost/server/v8@v8.0.0-20250519205859-65aec10162f6 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.5.0&&< 10.5.6 | 10.5.6go get github.com/mattermost/mattermost/server/v8@v10.5.6 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 9.11.0&&< 9.11.16 | 9.11.16go get github.com/mattermost/mattermost/server/v8@v9.11.16 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.8.0&&< 10.8.1 | 10.8.1go get github.com/mattermost/mattermost/server/v8@v10.8.1 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.7.0&&< 10.7.3 | 10.7.3go get github.com/mattermost/mattermost/server/v8@v10.7.3 |
Affected Products
mattermost servermattermostDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/mattermost/mattermost-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/mattermost/mattermost-server to 0.0.0-20250519205859-65aec10162f6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-4981 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Frequently Asked Questions
Is CVE-2025-4981 in your dependencies?
Find it across Go, including transitive dependencies.