GHSA-9h6j-4ffx-cm84 — v8
LOWGHSA-9h6j-4ffx-cm84 is a low-severity (CVSS 3) vulnerability in github.com/mattermost/mattermost/server/v8. A fix is available for github.com/mattermost/mattermost/server/v8 — see the affected versions and patch details below.
Mattermost doesn't restrict domains LLM can request to contact upstream
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-9h6j-4ffx-cm84 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 376,715 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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/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 <= 10.4.2, 10.5.x <= 10.5.0, 9.11.x <= 9.11.9 fail to restrict domains the LLM can request to contact upstream which allows an authenticated user to exfiltrate data from an arbitrary server accessible to the victim via performing a prompt injection in the AI plugin's Jira tool.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.5.0&&< 10.5.1 | 10.5.1go get github.com/mattermost/mattermost/server/v8@v10.5.1 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.4.0&&< 10.4.3 | 10.4.3go get github.com/mattermost/mattermost/server/v8@v10.4.3 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 9.11.0&&< 9.11.10 | 9.11.10go get github.com/mattermost/mattermost/server/v8@v9.11.10 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | all versions | 8.0.0-20250218121836-2b5275d87136go get github.com/mattermost/mattermost/server/v8@v8.0.0-20250218121836-2b5275d87136 |
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 10.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9h6j-4ffx-cm84 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-9h6j-4ffx-cm84 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-9h6j-4ffx-cm84. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-9h6j-4ffx-cm84 in your dependencies?
O3 Security finds GHSA-9h6j-4ffx-cm84 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.