Mattermost Playbooks fails to properly validate the props used by the RetrospectivePost custom post typeGHSA-3g36-gf7c-75qw
MEDIUMFix: mattermost/mattermost-plugin-playbooks@4c82309GHSA-3g36-gf7c-75qw is a medium-severity (CVSS 6.5) CWE-1287 vulnerability in github.com/mattermost/mattermost-plugin-playbooks. A fix is available for github.com/mattermost/mattermost-plugin-playbooks — see the affected versions and patch details below.
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 GHSA-3g36-gf7c-75qw.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/mattermost/mattermost-plugin-playbooks🐹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-plugin-playbooksReal-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 <= 9.11.10 fail to properly validate the props used by the RetrospectivePost custom post type in the Playbooks plugin, which allows an attacker to create a specially crafted post with maliciously crafted props and cause a denial of service (DoS) of the web app for all users.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost-plugin-playbooks | ≥ 2.0.0 | No fix |
| 🐹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 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.4.0 | No fix |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 10.5.0 | No fix |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 9.11.0 | No fix |
| 🐹Go | github.com/mattermost/mattermost-plugin-playbooks | all versions | 1.41.0go get github.com/mattermost/mattermost-plugin-playbooks@v1.41.0 |
Affected Products
mattermost servermattermostDetection & 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-plugin-playbooks, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
A fix is available for GHSA-3g36-gf7c-75qw; check the affected-versions list above or the advisory for the patched release of github.com/mattermost/mattermost-plugin-playbooks, then make sure no transitive dependency still pins the vulnerable range.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is GHSA-3g36-gf7c-75qw in your dependencies?
Find it across Go, including transitive dependencies.