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TI-2026-02693 Aliases CVE-2026-3116GHSA-f499-j7p4-wm44

Improper Input Validation in Zoom Plugin Webhook Handler

Priority LOW 22CWE-400Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-400.

Summary

Mattermost Plugins versions <=11.4 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to validate incoming request size which allows an authenticated attacker to cause service disruption via the webhook endpoint. Mattermost Advisory ID: MMSA-2026-00589

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00357 29th percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): 11.5.0, 11.4.1, 11.3.2 +2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

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 11.0.4; up to 11.1.3; up to 11.3.2; up to 10.11.1111.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12Patch availableCNA
  • Mattermost VendorMattermost Affected up to 11.0.4; up to 11.1.3; up to 11.3.2; up to 10.11.11 Fixed in 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*10.11.0 to before 10.11.12; 11.2.0 to before 11.2.4; 11.3.0 to before 11.3.2; 11.4.0 to before 11.4.1VulnerableMattermost
  • cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions 10.11.0 to before 10.11.12; 11.2.0 to before 11.2.4; 11.3.0 to before 11.3.2; 11.4.0 to before 11.4.1 Vulnerable ·Mattermost

Remediation

  • Fix · CNA Mattermost (Mattermost) Fixed in 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-3116
  2. 2026-10-03 Alias added: GHSA-f499-j7p4-wm44

References

Advisory 1

  • TI-2025-18933 Arbitrary file read in Mattermost Boards via import & export board archive CVSS 3.1CRITICAL 9.9
  • TI-2025-04465 Path Traversal Leading to RCE by Any Authenticated Mattermost User CVSS 3.1CRITICAL 9.9
  • TI-2017-14068 An issue was discovered in Mattermost Server before 3.6.2. CVSS 3.1CRITICAL 9.8
  • TI-2017-14060 An issue was discovered in Mattermost Server before 3.8.2, 3.7.5, and 3.6.7. CVSS 3.1CRITICAL 9.8
  • TI-2017-14048 An issue was discovered in Mattermost Server before 4.1.0, 4.0.4, and 3.10.3. CVSS 3.1CRITICAL 9.8
  • TI-2025-14360 Arbitrary file read via block duplication in Mattermost Boards CVSS 3.1CRITICAL 9.9
See all 505 →

Sources

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