{"action":"Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20260325160634-e738016c5920 or later.","affected":[{"fixed":"8.0.0-20260325160634-e738016c5920","introduced":"0"}],"component":"github.com/mattermost/mattermost/server/v8","cve_ids":["CVE-2026-6333"],"ecosystem":"Go","epss":0.00137,"exploited":false,"fixed_versions":["8.0.0-20260325160634-e738016c5920"],"ghsa_id":"GHSA-vqp5-2mrp-qqxg","id":"tcs_01M5KGP2E1HXT2BEHJBK7272HN","modified_at":"2026-06-25T23:01:38.693940001Z","published_at":"2026-06-25T22:34:38Z","references":["https://osv.dev/vulnerability/GO-2026-5671","https://github.com/advisories/GHSA-vqp5-2mrp-qqxg","https://nvd.nist.gov/vuln/detail/CVE-2026-6333","https://github.com/mattermost/mattermost/commit/e738016c592045e14bf926eafaeda6f8521def6d","https://mattermost.com/security-updates"],"severity":{"label":"unknown"},"sources":[{"source":"osv","source_id":"GO-2026-5671#Go/github.com/mattermost/mattermost/server/v8","url":"https://osv.dev/vulnerability/GO-2026-5671"}],"summary":"Mattermost doesn't validate the Host header when constructing response URLs for custom slash command in github.com/mattermost/mattermost-server"}