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
Metrics
Affected Vendors & Products
References
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| https://mattermost.com/security-updates |
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History
Fri, 23 Oct 2026 10:30:00 +0000
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Fri, 16 Oct 2026 15:30:00 +0000
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Fri, 16 Oct 2026 07:30:00 +0000
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| 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 | |
| Title | Mattermost fails to reject OAuth application sessions in account type switch, allowing account takeover via bearer token | |
| Weaknesses | CWE-863 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: Mattermost
Published: 2026-10-16T07:11:29.552Z
Updated: 2026-10-16T14:06:23.946Z
Reserved: 2026-08-06T09:52:03.711Z
Link: CVE-2026-19076
Updated: 2026-10-16T14:06:15.677Z
Status : Awaiting Analysis
Published: 2026-10-16T08:17:13.177
Modified: 2026-10-16T19:23:18.623
Link: CVE-2026-19076
No data.