CVE-2026-19076

medium

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

References

https://mattermost.com/security-updates

Details

Source: Mitre, NVD

Published: 2026-10-16

Updated: 2026-10-16

Risk Information

CVSS v2

Base Score: 4.6

Vector: CVSS2#AV:N/AC:H/Au:M/C:N/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 4.4

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

Severity: Medium