CVE-2025-3228 — mattermost-server
MEDIUMCVE-2025-3228 is a medium-severity (CVSS 4.3) CWE-863 vulnerability in github.com/mattermost/mattermost-server. A fix is available for github.com/mattermost/mattermost-server — see the affected versions and patch details below.
Unauthorized Guest user access to Playbook
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-2025-3228.
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
CVE-2025-3228 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🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8🐹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 10.5.x <= 10.5.5, 9.11.x <= 9.11.15, 10.8.x <= 10.8.0, 10.7.x <= 10.7.2, 10.6.x <= 10.6.5 fail to properly retrieve requestorInfo from playbooks handler for guest users which allows an attacker access to the playbook run.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost-server | all versions | 0.0.0-20250520060012-d0380305ef7ago get github.com/mattermost/mattermost-server@v0.0.0-20250520060012-d0380305ef7a |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | all versions | 8.0.0-20250520060012-d0380305ef7ago get github.com/mattermost/mattermost/server/v8@v8.0.0-20250520060012-d0380305ef7a |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.5.0&&< 10.5.6 | 10.5.6go get github.com/mattermost/mattermost/server/v8@v10.5.6 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 9.11.0&&< 9.11.16 | 9.11.16go get github.com/mattermost/mattermost/server/v8@v9.11.16 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.8.0&&< 10.8.1 | 10.8.1go get github.com/mattermost/mattermost/server/v8@v10.8.1 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.7.0&&< 10.7.3 | 10.7.3go get github.com/mattermost/mattermost/server/v8@v10.7.3 |
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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/mattermost/mattermost-server to 0.0.0-20250520060012-d0380305ef7a or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-3228 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 CVE-2025-3228 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-3228. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-3228 in your dependencies?
O3 Security finds CVE-2025-3228 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.