CVE-2025-9081 is a low-severity (CVSS 3.1) CWE-639 vulnerability in github.com/mattermost/mattermost-plugin-boards. A fix is available for github.com/mattermost/mattermost-plugin-boards — see the affected versions and patch details below.
IDOR in board file download allows any user to download any file by UUID
Exploitation Status
No confirmed exploitation observed yet
- 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-2025-9081.
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-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 | 0.0.0-20250716054606-3f3e3becfe1dgo get github.com/mattermost/mattermost-plugin-boards@v0.0.0-20250716054606-3f3e3becfe1d |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | all versions | 8.0.0-20250721095935-11c36f4d1e44go get github.com/mattermost/mattermost/server/v8@v8.0.0-20250721095935-11c36f4d1e44 |
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 10.5.0-rc1&&< 10.5.9 | 10.5.9go get github.com/mattermost/mattermost-server@v10.5.9 |
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 9.11.0-rc1&&< 9.11.18 | 9.11.18go get github.com/mattermost/mattermost-server@v9.11.18 |
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-plugin-boards, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2025-9081 in your dependencies?
Find it across Go, including transitive dependencies.