CVE-2026-4273 — Insufficient token rotation validation in remote cluster invite confirmation
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmati…
Published: 2026-05-18 · CVSS: 3.7 · CVSS 3.1
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a crafted invite confirmation with a RefreshedToken matching the original token. Mattermost Advisory ID: MMSA-2026-00575
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7