GHSA-fxwj-v664-wv5g
MEDIUMGHSA-fxwj-v664-wv5g is a medium-severity (CVSS 4.6) CWE-664 vulnerability in github.com/mattermost/mattermost-server/v6. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-fxwj-v664-wv5g is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Control of a Resource Through its Lifetime in Mattermost
Real-World Exposure
github.com/mattermost/mattermost-server/v6Real-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 6.4.x and earlier fails to properly invalidate pending email invitations when the action is performed from the system console, which allows accidentally invited users to join the workspace and access information from the public teams and channels.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost-server/v6 | all versions | 6.5.0 |
Research 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/v6. 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/v6 to 6.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fxwj-v664-wv5g 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-fxwj-v664-wv5g 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-fxwj-v664-wv5g. 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-fxwj-v664-wv5g in your dependencies?
O3 detects GHSA-fxwj-v664-wv5g across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.