PT-2026-25683 · Mattermost · Mattermost

Daw10 · Published 2026-02-13 · Updated 2026-03-27 · CVE-2026-2457

Positive Technologies (AI Summary)

CVSS v3.1

4.3

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Mattermost versions 11.3.0 and earlier Mattermost versions 11.2.2 and earlier Mattermost versions 10.11.10 and earlier

Description The software does not properly sanitize client-supplied post metadata. This allows an authenticated attacker to spoof permalink embeds, impersonating other users by sending crafted PUT requests to the post update API endpoint, ''/api/v1/posts/{post id}''. The vulnerable parameter is the post metadata within the PUT request.

Recommendations Update Mattermost to a version later than 11.3.0. Update Mattermost to a version later than 11.2.2. Update Mattermost to a version later than 10.11.10.

Fix

Origin Validation Error

Weakness Enumeration

CWE-346

Related Identifiers

BDU:2026-06572

CVE-2026-2457

GHSA-PH22-FW5M-W2Q9

GO-2026-4732

SUSE-SU-2026:1135-1

Affected Products

Mattermost

References · 151

• https://osv.dev/vulnerability/SUSE-SU-2026:1135-1 · Vendor Advisory
• https://bdu.fstec.ru/vul/2026-06572 · Security Note
• https://mattermost.com/security-updates · Vendor Advisory
• https://osv.dev/vulnerability/GO-2026-4732 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-2457 · Security Note
• https://osv.dev/vulnerability/CVE-2026-2457 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-ph22-fw5m-w2q9 · Vendor Advisory
• https://github.com/mattermost/mattermost · Note
• https://github.com/mattermost/mattermost/commit/9efe617be8b8f1d036e12721e8e73b69a543ed34 · Note
• https://suse.com/security/cve/CVE-2026-22545 · Note
• https://suse.com/security/cve/CVE-2026-33281 · Note
• https://suse.com/security/cve/CVE-2026-33132 · Note
• https://suse.com/security/cve/CVE-2026-33191 · Note
• https://suse.com/security/cve/CVE-2026-33066 · Note
• https://suse.com/security/cve/CVE-2026-33315 · Note