{"id":"CVE-2026-19076","title":"Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to reject OAuth application sessions in the account type switch endpoint, which allows an attacker with a valid OAuth bearer token for a ta…","summary":"Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to reject OAuth application sessions in the account type switch endpoint, which allows an attacker with a valid OAuth bearer token for a ta…","severity":"medium","cvss":4.4,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N","cwe":["CWE-863"],"vendor":"Mattermost","product":"Mattermost","affected":["Mattermost >= 11.10.0 <= 11.10.0","Mattermost >= 11.7.0 <= 11.7.9","Mattermost >= 11.9.0 <= 11.9.1","Mattermost >= 11.8.0 <= 11.8.5"],"published":"2026-10-16","updated":"2026-10-16","sourceUpdated":"2026-10-16T19:23:18.623","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-19076","references":[{"url":"https://mattermost.com/security-updates","label":"responsibledisclosure@mattermost.com"}],"tags":["nvd","cve.org"],"epss":0.00197,"epssPercentile":0.09403,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-16T14:06:08.450522Z"},"ingestedAt":"2026-10-16T08:02:23.122Z","slug":"CVE-2026-19076","body":"## Overview\n\nMattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to reject OAuth application sessions in the account type switch endpoint, which allows an attacker with a valid OAuth bearer token for a target user to permanently take over that user's SSO-backed account by setting an attacker-controlled password and detaching the account from its identity provider via a crafted request to POST /api/v4/users/login/switch.. Mattermost Advisory ID: MMSA-2026-00758\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":24.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}