CVE-2026-0999 — Authentication bypass via userID login when email and username login are disabled

CVE-2026-0999

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

Description (CNA)

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

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.1.0 through 11.1.2; affected 10.11.0 through 10.11.9; affected 11.2.0 through 11.2.1; unaffected 11.3.0; unaffected 11.1.3; unaffected 10.11.10; unaffected 11.2.2

CWE

CWE-303

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.