CVE-2026-3524

Authorization Bypass in Mattermost Legal Hold Plugin Due to Missing Return After Permission Check

CVSS 8.3 HIGHEPSS 0.4%CWE-862

Vexday Risk Score

21Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 8.3EPSS 0.4%KEV nãoPoC —Nuclei —Metasploit —Patch referenciado

Lifecycle

06 Apr 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

Mattermost Plugin Legal Hold versions <=1.1.4 fail to halt request processing after a failed authorization check in ServeHTTP which allows an authenticated attacker to access, create, download, and delete legal hold data via crafted API requests to the plugin's endpoints. Mattermost Advisory ID: MMSA-2026-00621

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

Affected products

Mattermost · Mattermost

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References

https://mattermost.com/security-updates