CVE-2026-19076
CVE-2026-19076 · Mattermost fails to reject OAuth application sessions in account type switch, allowing account takeover via bearer token
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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
CVSS 4.4 · Medium · EPSS 0.2% · Fix available
- Published
- Updated
Affected products and versions
mattermost
- Versions
- ≥ 11.10.0, ≤ 11.10.0: Affected (semver)
- ≥ 11.7.0, ≤ 11.7.9: Affected (semver)
- ≥ 11.9.0, ≤ 11.9.1: Affected (semver)
- ≥ 11.8.0, ≤ 11.8.5: Affected (semver)
- 11.11.0: Not affected
- 11.10.1: Not affected
- 11.7.10: Not affected
- 11.9.2: Not affected
- 11.8.6: Not affected
Update to 11.10.1; Update to 11.7.10; Update to 11.8.6; Update to 11.9.2