{"action":"Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20260130144323-5bb5261c72fa or later.","affected":[{"fixed":"8.0.0-20260130144323-5bb5261c72fa","introduced":"0"}],"component":"github.com/mattermost/mattermost/server/v8","cve_ids":["CVE-2026-21386"],"ecosystem":"Go","epss":0.00187,"exploited":false,"fixed_versions":["8.0.0-20260130144323-5bb5261c72fa"],"ghsa_id":"GHSA-5mr9-crcg-8wh2","id":"tcs_01M5KEYJK6E28KHBJZ0Q8WBQVM","modified_at":"2026-03-23T18:56:15.398070Z","published_at":"2026-03-16T15:30:46Z","references":["https://osv.dev/vulnerability/GHSA-5mr9-crcg-8wh2","https://nvd.nist.gov/vuln/detail/CVE-2026-21386","https://github.com/mattermost/mattermost/commit/5bb5261c72faa476558a694c23581d24b734da41","https://github.com/mattermost/mattermost","https://mattermost.com/security-updates"],"severity":{"label":"medium","score":4.3},"sources":[{"source":"osv","source_id":"GHSA-5mr9-crcg-8wh2","url":"https://osv.dev/vulnerability/GHSA-5mr9-crcg-8wh2"}],"summary":"Mattermost fails to use consistent error responses when handling the /mute command"}