{"id":"GHSA-vqp5-2mrp-qqxg","revision":"c2bc997ef02845ccb3b95002e6aba51c","records":[{"revision":"c2bc997ef02845ccb3b95002e6aba51c","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-vqp5-2mrp-qqxg","aliases":["CVE-2026-6333","GO-2026-5671"],"title":"Mattermost doesn't validate the Host header when constructing response URLs for custom slash command","description":"Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an attacker-controlled server via a spoofed Host header.. Mattermost Advisory ID: MMSA-2026-00582","state":0,"publishedAt":"2026-05-18T09:31:48+00:00","modifiedAt":"2026-06-25T23:11:07.7988389+00:00","affected":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"11.5.0"},{"kind":"fixed","version":"11.5.2"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"10.11.0"},{"kind":"fixed","version":"10.11.14"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"8.0.0-20260325160634-e738016c5920"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"5.3.2-0.20260325160634-e738016c5920"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"LOW"}],"references":["https://nvd.nist.gov/vuln/detail/CVE-2026-6333","https://github.com/mattermost/mattermost/commit/e738016c592045e14bf926eafaeda6f8521def6d","https://github.com/mattermost/mattermost","https://mattermost.com/security-updates"],"sourceUrl":"https://github.com/advisories/GHSA-vqp5-2mrp-qqxg","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-vqp5-2mrp-qqxg","identifiers":["GHSA-vqp5-2mrp-qqxg","CVE-2026-6333","GO-2026-5671"]},"retained":false,"historicalAffected":[]}],"coverage":[]}