{"id":"CVE-2026-4273","title":"Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token ro…","summary":"Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token ro…","severity":"low","cvss":3.7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","cwe":["CWE-863"],"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-2026-4273","references":[{"url":"https://mattermost.com/security-updates","label":"responsibledisclosure@mattermost.com"}],"tags":["nvd"],"epss":0.00237,"epssPercentile":0.13629,"ingestedAt":"2026-10-14T20:53:12.296Z","slug":"CVE-2026-4273","body":"## Overview\n\nMattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a crafted invite confirmation with a RefreshedToken matching the original token. Mattermost Advisory ID: MMSA-2026-00575\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":20,"depthScoreParts":{"impact":20.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}