CVE-2026-28741 PUBLISHED

CSRF Protection Bypass Allows Updating a User's Authentication Method

Assigner: Mattermost
Reserved: 10.03.2026 Published: 15.04.2026 Updated: 15.04.2026

Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to validate CSRF tokens on an authentication endpoint which allows an attacker to update a user's authentication method via a CSRF attack by tricking a user into visiting a malicious page. Mattermost Advisory ID: MMSA-2026-00625

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
CVSS Score: 6.8

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	Mattermost
Product	Mattermost
Versions	Default: unaffected affected from 10.11.0 to 10.11.12 (incl.) affected from 11.5.0 to 11.5.0 (incl.) affected from 11.4.0 to 11.4.2 (incl.) affected from 11.3.0 to 11.3.2 (incl.) Version 10.11.13 is unaffected Version 11.5.1 is unaffected Version 11.4.3 is unaffected Version 11.3.3 is unaffected

Solutions

Update Mattermost to versions 10.11.13, 11.5.1, 11.4.3, 11.3.3 or higher.

Credits

Eva Sarafianou finder

References

MMSA-2026-00625

Problem Types

CWE-352: Cross-Site Request Forgery (CSRF) CWE