Go/github.com/mattermost/mattermost/server/v8 CVE-2026-5163: medium 6.5, EPSS 0.21%
Mattermost doesn't verify channel membership when processing AI-assisted message rewrites
Action: Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20260401090745-f4d1abe7e8f5 or later.
go get github.com/mattermost/mattermost/server/v8@v11.5.2go get github.com/mattermost/mattermost/server/v8@v8.0.0-20260401090745-f4d1abe7e8f5Affected
| introduced | fixed | last affected |
|---|---|---|
| 11.5.0 | 11.5.2 | - |
| 0 | 8.0.0-20260401090745-f4d1abe7e8f5 | - |
Fixed versions
| 11.5.2 | 8.0.0-20260401090745-f4d1abe7e8f5 |
Sources
- osv: GHSA-8r89-8w26-cq32
- https://nvd.nist.gov/vuln/detail/CVE-2026-5163
- https://github.com/mattermost/mattermost/commit/f4d1abe7e8f545f1a87f463fa9fe451c731aebf8
- https://github.com/mattermost/mattermost
- https://mattermost.com/security-updates
CVE-2026-5163 · published · modified · JSON