Go/github.com/mattermost/mattermost-server CVE-2026-5163: unknown, EPSS 0.21%
Mattermost doesn't verify channel membership when processing AI-assisted message rewrites in github.com/mattermost/mattermost-server
Action: Upgrade github.com/mattermost/mattermost-server to 11.5.2+incompatible or later.
go get github.com/mattermost/mattermost-server@v11.5.2+incompatibleAffected
| introduced | fixed | last affected |
|---|---|---|
| 11.5.0+incompatible | 11.5.2+incompatible | - |
Fixed versions
| 11.5.2+incompatible |
Sources
- osv: GO-2026-5263
- https://github.com/advisories/GHSA-8r89-8w26-cq32
- https://nvd.nist.gov/vuln/detail/CVE-2026-5163
- https://github.com/mattermost/mattermost/commit/f4d1abe7e8f545f1a87f463fa9fe451c731aebf8
- https://mattermost.com/security-updates
CVE-2026-5163 · published · modified · JSON