PT-2026-8338 · Mattermost · Mattermost

Daw10 · Published 2026-02-16 · Updated 2026-03-03 · CVE-2025-13821

Positive Technologies (AI Summary)

CVSS v3.1

5.7

Medium

Base vector

AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

Name of the Vulnerable Software and Affected Versions Mattermost versions 10.11.x through 10.11.9 Mattermost versions 11.1.x through 11.1.2 Mattermost versions 11.2.x through 11.2.1

Description The software does not properly sanitize sensitive data within WebSocket messages. This allows authenticated users to obtain password hashes and multi-factor authentication secrets by exploiting profile nickname updates or email verification events.

Recommendations Update Mattermost to a version later than 10.11.9. Update Mattermost to a version later than 11.1.2. Update Mattermost to a version later than 11.2.1.

Fix

Information Disclosure

Weakness Enumeration

CWE-200

Related Identifiers

CVE-2025-13821

GHSA-PP9J-PF5C-659X

GO-2026-4524

SUSE-SU-2026:0757-1

Affected Products

Mattermost

References · 116

• https://osv.dev/vulnerability/GHSA-pp9j-pf5c-659x · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-13821 · Security Note
• https://osv.dev/vulnerability/SUSE-SU-2026:0757-1 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-13821 · Vendor Advisory
• https://mattermost.com/security-updates · Vendor Advisory
• https://osv.dev/vulnerability/GO-2026-4524 · Vendor Advisory
• https://github.com/mattermost/mattermost · Note
• https://github.com/mattermost/mattermost/commit/cd17b61de41bf0a49b524bb91ce0bbe859e5a100 · Note
• https://t.me/CVEtracker/44813 · Telegram Post
• https://suse.com/security/cve/CVE-2025-64111 · Note
• https://suse.com/security/cve/CVE-2026-0998 · Note
• https://suse.com/security/cve/CVE-2026-22892 · Note
• https://suse.com/security/cve/CVE-2026-24122 · Note
• https://suse.com/security/cve/CVE-2026-21434 · Note
• https://suse.com/security/cve/CVE-2026-25760 · Note