PT-2026-41643 · Mattermost · Mattermost

Daw10 · CVE-2026-4273 · Published 2026-05-18 · Updated 2026-07-30

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 11.5.0 through 11.5.1 Mattermost versions 10.11.0 through 10.11.13

Description Insufficient token rotation validation occurs during remote cluster invite confirmation. An authenticated attacker can bypass token rotation and reuse the original invite token by sending a crafted invite confirmation where the RefreshedToken matches the original token.

Recommendations Update versions 11.5.0 through 11.5.1 to a version newer than 11.5.1. Update versions 10.11.0 through 10.11.13 to a version newer than 10.11.13.

Exploit

Fix

DoS

Incorrect Authorization

Weakness Enumeration

CWE-863

Related Identifiers

CVE-2026-4273

GHSA-HQPJ-F3JH-29VX

GO-2026-5432

OPENSUSE-SU-2026:21483-1

Affected Products

Mattermost

References · 1746

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4273.json · Exploit
• https://mattermost.com/security-updates · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-4273 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-hqpj-f3jh-29vx · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-4273 · Security Note
• https://osv.dev/vulnerability/GO-2026-5432 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2026:21483-1 · Vendor Advisory
• https://github.com/mattermost/mattermost/commit/742e0be9507454a7e662668e1d9ec1b94b636e9b · Note
• https://github.com/mattermost/mattermost · Note
• https://suse.com/security/cve/CVE-2025-65797 · Note
• https://suse.com/security/cve/CVE-2026-44427 · Note
• https://suse.com/security/cve/CVE-2026-27589 · Note
• https://suse.com/security/cve/CVE-2026-7736 · Note
• https://suse.com/security/cve/CVE-2026-27137 · Note
• https://suse.com/security/cve/CVE-2026-25232 · Note