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TI-2026-03035 Aliases CVE-2026-3524GHSA-h7g6-pq3g-f7cw

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

Priority LOW 38CWE-862Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-862.

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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00385 32nd percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): 1.1.5

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MattermostMattermostup to 1.1.41.1.5Patch availableCNA
  • Mattermost VendorMattermost Affected up to 1.1.4 Fixed in 1.1.5 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mattermost:legal_hold:*:*:*:*:*:mattermost:*:*before 1.1.5VulnerableMattermost
  • cpe:2.3:a:mattermost:legal_hold:*:*:*:*:*:mattermost:*:* Versions before 1.1.5 Vulnerable ·Mattermost

Remediation

  • Fix · CNA Mattermost (Mattermost) Fixed in 1.1.5

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-3524
  2. 2026-10-03 Alias added: GHSA-h7g6-pq3g-f7cw

References

Advisory 1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences