CVE-2026-0999CWE-303

Authentication bypass via userID login when email and username login are disabled

Medium · published February 16, 2026

CVSS v3.1
5.4
EPSS
0%
Percentile
9.4
In the wild
Unconfirmed
What it is

Mattermost versions 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 11.2.1 fail to properly validate login method restrictions which allows an authenticated user to bypass SSO-only login requirements via userID-based authentication. Mattermost Advisory ID: MMSA-2025-00548

The record
Technical detail
CVSS v3.1
5.4 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00200 · 9.4th percentile
Weakness
CWE-303 · Incorrect Implementation of Authentication Algorithm
Published
2026-02-16T09:47Z
EPSS history
Timeline
  • 16 FEB 09:47Z
    Authentication bypass via userID login when email and username login are disabled
    cvelistv5