{"id":"CVE-2026-19076","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-19076","generatedAt":"2026-10-28T06:35:34.583Z","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 target user to…","description":"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 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","published":"2026-10-16T08:17:13.000Z","lastModified":"2026-10-27T20:57:34.000Z","status":"Analyzed","sourceIdentifier":"responsibledisclosure@mattermost.com","cvss":{"version":"3.1","score":4.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N"},"cwe":["CWE-863"],"affected":["mattermost/mattermost server"],"epss":{"score":0.00197,"percentile":0.09403,"date":"2026-10-27","history":[{"date":"2026-10-16","score":0.00197,"percentile":0.08856}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.20%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-16T08:17:13.000Z","detail":{"score":"4.4","severity":"MEDIUM","publishedAt":"2026-10-16T08:17:13.177Z"},"summary":"New CVE, medium severity (CVSS 4.9)."}],"references":[{"url":"https://mattermost.com/security-updates","tags":["Vendor Advisory"],"source":"responsibledisclosure@mattermost.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-19076","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}