{"id":"GHSA-jp3f-x449-4q75","summary":"Mattermost doesn't enforce client identity binding during the OAuth authorization code redemption flow","details":"Mattermost versions 11.5.x \u003c= 11.5.1, 10.11.x \u003c= 10.11.13 fail to enforce client identity binding during the OAuth authorization code redemption flow which allows an authenticated OAuth client to redeem authorization codes issued to a different client via a crafted token exchange request.. Mattermost Advisory ID: MMSA-2026-00570","aliases":["CVE-2026-6334","GO-2026-5474"],"modified":"2026-06-25T23:11:46.117587494Z","published":"2026-05-18T09:31:47Z","database_specific":{"severity":"LOW","github_reviewed":true,"github_reviewed_at":"2026-06-01T15:04:48Z","nvd_published_at":"2026-05-18T08:16:14Z","cwe_ids":["CWE-305"]},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6334"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/e9ae890a013bb57989fcbdb548d8b7b86b240237"},{"type":"PACKAGE","url":"https://github.com/mattermost/mattermost"},{"type":"WEB","url":"https://mattermost.com/security-updates"}],"affected":[{"package":{"name":"github.com/mattermost/mattermost/server/v8","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.5.0"},{"fixed":"11.5.2"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-jp3f-x449-4q75/GHSA-jp3f-x449-4q75.json"}},{"package":{"name":"github.com/mattermost/mattermost/server/v8","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8"},"ranges":[{"type":"SEMVER","events":[{"introduced":"10.11.0"},{"fixed":"10.11.14"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-jp3f-x449-4q75/GHSA-jp3f-x449-4q75.json"}},{"package":{"name":"github.com/mattermost/mattermost/server/v8","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"8.0.0-20260318173148-e9ae890a013b"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-jp3f-x449-4q75/GHSA-jp3f-x449-4q75.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.3.2-0.20260318173148-e9ae890a013b"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-jp3f-x449-4q75/GHSA-jp3f-x449-4q75.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:N"}]}