CVE-2026-19076

Published: Oct 16, 2026Modified: Oct 16, 2026

4.4

Vector

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N

Exploitability: 0.7 / Impact: 3.6

Source: responsibledisclosure@mattermost.com (Secondary)

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

Related CWEs

CWE-863

Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions.

References (1)

https://mattermost.com/security-updates

Source: responsibledisclosure@mattermost.com

Timeline

No history available yet.