CVE-2025-9081
LOWCVE-2025-9081 is a low-severity (CVSS 3.1) CWE-639 vulnerability in github.com/mattermost/mattermost-plugin-boards. O3 Security confirms whether CVE-2025-9081 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
IDOR in board file download allows any user to download any file by UUID
Real-World Exposure
github.com/mattermost/mattermost-plugin-boards🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost-server🐹github.com/mattermost/mattermost-serverReal-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 <= 10.5.8, 9.11.x <= 9.11.17 fail to properly validate access controls which allows any authenticated user to download sensitive files via board file download endpoint using UUID enumeration
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost-plugin-boards | all versions | 0.0.0-20250716054606-3f3e3becfe1d |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | all versions | 8.0.0-20250721095935-11c36f4d1e44 |
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 10.5.0-rc1&&< 10.5.9 | 10.5.9 |
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 9.11.0-rc1&&< 9.11.18 | 9.11.18 |
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-plugin-boards. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/mattermost/mattermost-plugin-boards to 0.0.0-20250716054606-3f3e3becfe1d or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-9081 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-9081 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-9081. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-9081 in your dependencies?
O3 detects CVE-2025-9081 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.