Vulnerability details

CVE-2026-3524

Mattermost Mattermost

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

CVSS 3.1

8.3High

Official description

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 scores

Score	Version	Source	Vector
8.3High	3.1	CVEProject cvelistV5 (CNA) (Mattermost)	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`

Affected products

Vendor	Product	Versions	Source
Mattermost	Mattermost	v ≤ 1.1.4	CVEProject cvelistV5 (CNA)

References and advisories

https://mattermost.com/security-updates vendor-advisory

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Details

Published: 2026-04-06
Last updated: 2026-04-07
State: Published
Assigner (CNA): Mattermost

Exploit prediction (EPSS)

0.38%

Probability of exploitation in 30 days

32.7%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: No
Exploitation: None
Technical impact: Total

Weaknesses (CWE)

CWE-862
Missing Authorization