| id: GO-2026-4744 |
| modules: |
| - module: github.com/mattermost/mattermost-server |
| versions: |
| - introduced: 10.11.0-rc1+incompatible |
| - fixed: 10.11.11+incompatible |
| - introduced: 11.2.0-rc1+incompatible |
| - fixed: 11.2.3+incompatible |
| - introduced: 11.3.0-rc1+incompatible |
| - fixed: 11.3.1+incompatible |
| vulnerable_at: 11.3.1-rc1+incompatible |
| - module: github.com/mattermost/mattermost-server/v5 |
| non_go_versions: |
| - fixed: 5.3.2-0.20260130144323-5bb5261c72fa |
| vulnerable_at: 5.39.3 |
| - module: github.com/mattermost/mattermost-server/v6 |
| vulnerable_at: 6.7.2 |
| - module: github.com/mattermost/mattermost/server/v8 |
| versions: |
| - fixed: 8.0.0-20260130144323-5bb5261c72fa |
| skip_lint: true |
| summary: |- |
| Mattermost fails to use consistent error responses when handling the /mute |
| command in github.com/mattermost/mattermost-server |
| cves: |
| - CVE-2026-21386 |
| ghsas: |
| - GHSA-5mr9-crcg-8wh2 |
| references: |
| - advisory: https://github.com/advisories/GHSA-5mr9-crcg-8wh2 |
| - advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-21386 |
| - web: https://github.com/mattermost/mattermost/commit/5bb5261c72faa476558a694c23581d24b734da41 |
| - web: https://mattermost.com/security-updates |
| notes: |
| - fix: 'github.com/mattermost/mattermost/server/v8: could not add vulnerable_at: could not find tagged version between introduced and fixed' |
| source: |
| id: GHSA-5mr9-crcg-8wh2 |
| created: 2026-03-23T13:00:58.649716295-04:00 |
| review_status: UNREVIEWED |
