CVE-2026-6339mediumCWE-346

Missing request origin validation on burn-on-read reveal endpoint

13Vexday Risk Score

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

ssvc Trackcvss 4.3epss 0.1%

probabilidade de exploração

0.1%top 98% das CVEs

exploração observada

nãonenhuma fonte reporta

Mattermost versions 11.5.x <= 11.5.1, 11.4.x <= 11.4.3 fail to validate the X-Requested-With header on the burn-on-read reveal endpoint which allows an authenticated channel member to force the reveal of a burn-on-read message without recipient consent via a crafted Markdown image tag.. Mattermost Advisory ID: MMSA-2026-00636

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Produtos afetados

Mattermost · Mattermost

Referências

https://mattermost.com/security-updates