How severe is GHSA-jf5h-xfw4-p8gp?

GHSA-jf5h-xfw4-p8gp has a CVSS score of 3/10, rated LOW. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-jf5h-xfw4-p8gp?

GHSA-jf5h-xfw4-p8gp affects the following packages: github.com/mattermost/mattermost/server/v8 (Go), github.com/mattermost/mattermost (Go), github.com/mattermost/mattermost (Go), github.com/mattermost/mattermost-plugin-github (Go). Ecosystems affected: Go.

How do I fix GHSA-jf5h-xfw4-p8gp?

Update github.com/mattermost/mattermost/server/v8 to 10.11.7-0.20251106103514-3b05384dd014 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-jf5h-xfw4-p8gp is resolved across your whole dependency graph.

How do I detect GHSA-jf5h-xfw4-p8gp in my Go dependencies?

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.

How do I mitigate GHSA-jf5h-xfw4-p8gp if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-jf5h-xfw4-p8gp?

O3 pinpoints whether GHSA-jf5h-xfw4-p8gp is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-jf5h-xfw4-p8gp actively exploited in the wild?

No public exploit code has been indexed for GHSA-jf5h-xfw4-p8gp yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-jf5h-xfw4-p8gp?

GHSA-jf5h-xfw4-p8gp has an EPSS (Exploit Prediction Scoring System) score of 0.1%, placing it in the 4th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was GHSA-jf5h-xfw4-p8gp published, and has it been updated?

GHSA-jf5h-xfw4-p8gp was published on December 17, 2025 and was last updated on December 22, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

GHSA-jf5h-xfw4-p8gp: v8 (Low 3)

EPSS Exploitation Probability

via FIRST.org ↗

0.1%probability of exploitation in next 30 days

Lower Risk4th percentile+0.09%

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.

Blast Radius

4 pkgs affected

🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost🐹github.com/mattermost/mattermost🐹github.com/mattermost/mattermost-plugin-github

Real-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 10.11.x <= 10.11.6 and Mattermost GitHub plugin versions <=2.4.0 fail to validate plugin bot identity in reaction forwarding which allows attackers to hijack the GitHub reaction feature to make users add reactions to arbitrary GitHub objects via crafted notification posts.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/mattermost/mattermost/server/v8`	≥ 10.11.0-rc1&&< 10.11.7-0.20251106103514-3b05384dd014	10.11.7-0.20251106103514-3b05384dd014
🐹Go	`github.com/mattermost/mattermost`	all versions	10.11.7-0.20251106103514-3b05384dd014
🐹Go	`github.com/mattermost/mattermost`	≥ 11.0.0-alpha.1&&< 11.1.0	11.1.0
🐹Go	`github.com/mattermost/mattermost-plugin-github`	all versions	1.0.1-0.20250829075715-0deffcfc6bee

Detection & mitigation playbook

Open-source dependency

Detect
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 10.11.7-0.20251106103514-3b05384dd014 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-jf5h-xfw4-p8gp 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-jf5h-xfw4-p8gp 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-jf5h-xfw4-p8gp. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Mattermost versions 10.11.x <= 10.11.6 and Mattermost GitHub plugin versions <=2.4.0 fail to validate plugin bot identity in reaction forwarding which allows attackers to hijack the GitHub reaction feature to make users add reactions to arbitrary GitHub objects via crafted notification posts.

O3 Security · Impact-Aware SCA

Is GHSA-jf5h-xfw4-p8gp in your dependencies?

O3 detects GHSA-jf5h-xfw4-p8gp across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

GHSA-jf5h-xfw4-p8gp