CVE-2026-3524 json
Authorization Bypass in Mattermost Legal Hold Plugin Due to Missing Return After Permission Check
published 7mo ago modified 3mo ago also EUVD-2026-19231
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 32%
- public exploits
- 0
- none known
Summary
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
Patch / fix
- Mattermost Mattermost 1.1.5
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 7mo ago
Exploit prediction
0.39% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
- Mattermost Mattermost
Classification
- Weakness
-
- CWE-862 Missing Authorization
References
-
mattermost.com
/security-updates
vendor-advisory
Sources
- CVE List CVE-2026-3524
- NVD CVE-2026-3524
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