CVE-2026-27656

MEDIUM

5.7

Descripcion

Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to properly validate user identity in the OpenID {{IsSameUser()}} comparison logic, which allows an attacker to take over arbitrary user accounts via an overly permissive substring matching flaw in the user discovery flow.. Mattermost Advisory ID: MMSA-2026-00590

Detalles CVE

Puntuacion CVSS v3.15.7

SeveridadMEDIUM

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

Vector de ataqueNETWORK

ComplejidadHIGH

Privilegios requeridosHIGH

Interaccion usuarioREQUIRED

Publicado3/25/2026

Ultima modificacion3/26/2026

Fuentenvd

Avistamientos honeypot0

Productos afectados

mattermost:mattermost_server

Debilidades (CWE)

CWE-303

Referencias

https://mattermost.com/security-updates(responsibledisclosure@mattermost.com)

Correlaciones IOC

Sin correlaciones registradas

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