CVE-2026-27656mediumCWE-303

CVE-2026-27656: falha de média gravidade em Mattermost

Account Takeover via Substring Matching in OpenID Connect Authentication

Publicada em · Atualizada em

13Vexday Risk Score

Sem sinal de exploração. Nenhum artefato público de exploração conhecido até agora.

ssvc Trackcvss 5.7epss 0.3%
probabilidade de exploração
0.3%top 78% das CVEs
exploração observada
nãonenhuma fonte reporta
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
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N
Produtos afetados
Mattermost · Mattermost
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No mesmo produto, das mais perigosas para as menos.

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Referências
https://mattermost.com/security-updates