4.3

CVE-2026-6339

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

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
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Mattermost ≫ Mattermost Server Version >= 11.4.0 < 11.4.4
Mattermost ≫ Mattermost Server Version >= 11.5.0 < 11.5.2
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.11% 0.017
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 4.3 2.8 1.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
responsibledisclosure@mattermost.com 4.3 2.8 1.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CWE-346 Origin Validation Error

The product does not properly verify that the source of data or communication is valid.

https://mattermost.com/security-updates
Vendor Advisory