{"id":"CVE-2026-6334","title":"Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 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 di…","summary":"Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 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 di…","severity":"low","cvss":3.1,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:N","cwe":["CWE-305"],"vendor":"mattermost","product":"mattermost_server","affected":["mattermost_server >= 10.11.0, < 10.11.14","mattermost_server >= 11.5.0, < 11.5.2"],"patched":["mattermost_server 11.5.2"],"published":"2026-05-18","updated":"2026-10-14","sourceUpdated":"2026-10-14T20:10:00.190","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-6334","references":[{"url":"https://mattermost.com/security-updates","label":"responsibledisclosure@mattermost.com"}],"tags":["nvd"],"epss":0.002,"epssPercentile":0.09175,"ingestedAt":"2026-10-14T20:53:12.297Z","slug":"CVE-2026-6334","body":"## Overview\n\nMattermost versions 11.5.x <= 11.5.1, 10.11.x <= 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\n\n## Affected\n\n- `mattermost_server >= 10.11.0, < 10.11.14`\n- `mattermost_server >= 11.5.0, < 11.5.2`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `mattermost_server 11.5.2`","depth":"sunlit","depthScore":17,"depthScoreParts":{"impact":17.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}