CVE-2025-25279 is a critical-severity (CVSS 9.9) Path Traversal vulnerability in github.com/mattermost/mattermost/server/v8. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for github.com/mattermost/mattermost/server/v8 — see the affected versions and patch details below.
Arbitrary file read in Mattermost Boards via import & export board archive
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-2025-25279.
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/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 10.4.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 board blocks when importing boards which allows an attacker could read any arbitrary file on the system via importing and exporting a specially crafted import archive in Boards.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost/server/v8 | all versions | 8.0.0-20250122165010-4ed702ccff4ego get github.com/mattermost/mattermost/server/v8@v8.0.0-20250122165010-4ed702ccff4e |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 9.11.0-rc1&&< 9.11.8 | 9.11.8go get github.com/mattermost/mattermost/server/v8@v9.11.8 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.2.0-rc1&&< 10.2.3 | 10.2.3go get github.com/mattermost/mattermost/server/v8@v10.2.3 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.3.0-rc1&&< 10.3.3 | 10.3.3go get github.com/mattermost/mattermost/server/v8@v10.3.3 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.4.0-rc1&&< 10.4.2 | 10.4.2go get github.com/mattermost/mattermost/server/v8@v10.4.2 |
Affected Products
mattermost servermattermostResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & 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/v8, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/mattermost/mattermost/server/v8 to 8.0.0-20250122165010-4ed702ccff4e or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-25279 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-2025-25279 in your dependencies?
Find it across Go, including transitive dependencies.