GHSA-vww6-79rv-3j4x
MEDIUMGHSA-vww6-79rv-3j4x is a medium-severity (CVSS 4.1) CWE-863 vulnerability in github.com/mattermost/mattermost/server/v8. O3 Security confirms whether GHSA-vww6-79rv-3j4x is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Mattermost doesn't verify that post actions invoking `/share-issue-publicly` were created by the Jira plugin
Blast Radius
github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost-server🐹github.com/mattermost/mattermost-server🐹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 11.1.x <= 11.1.0, 11.0.x <= 11.0.5, 10.12.x <= 10.12.3, 10.11.x <= 10.11.7 fail to verify that post actions invoking /share-issue-publicly were created by the Jira plugin which allowed a malicious Mattermost user to exfiltrate Jira tickets when victim users interacted with affected posts
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost/server/v8 | all versions | 8.0.0-20251121122154-b57c297c6d7 |
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 10.11.0&&< 10.11.8 | 10.11.8 |
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 10.12.0&&< 10.12.4 | 10.12.4 |
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 11.0.0&&< 11.0.6 | 11.0.6 |
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 11.1.0&&< 11.1.1 | 11.1.1 |
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. 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/server/v8 to 8.0.0-20251121122154-b57c297c6d7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vww6-79rv-3j4x 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 GHSA-vww6-79rv-3j4x 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 GHSA-vww6-79rv-3j4x. 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-vww6-79rv-3j4x in your dependencies?
O3 detects GHSA-vww6-79rv-3j4x across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.