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TI-2026-80405 Aliases CVE-2026-116516GHSA-p4vm-rgr6-x9pc

Crash in Mattermost Agents plugin via Zoom chat transcription

Priority LOW 29CWE-754Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

Mattermost versions up to and including 11.9, 11.1.9, 11.5.8 and 11.10.7.0 fail to validate the length of Zoom chat lines before slicing them. An authenticated attacker can crash the Agents plugin by summarizing a Zoom chat transcription that contains short continuation lines. The flaw is an improper check for unusual or exceptional conditions (CWE-754).

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

Mattermost versions <=11.9 11.1.9 11.5.8 11.10.7.0 fail to validate Zoom chat line length before slicing which allows an authenticated attacker to crash the Agents plugin via summarizing a Zoom chat transcription containing short continuation lines. Mattermost Advisory ID: MMSA-2026-00723

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00362 30th percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): 11.10.0, 11.9.2, 11.8.6 +1

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
MattermostMattermost<=11.9 11.1.9 11.5.8 11.10.7.0 – <=11.9 11.1.9 11.5.8 11.10.7.011.10.0, 11.9.2, 11.8.6, 11.7.11Patch availableCNA
  • Mattermost VendorMattermost Affected <=11.9 11.1.9 11.5.8 11.10.7.0 – <=11.9 11.1.9 11.5.8 11.10.7.0 Fixed in 11.10.0, 11.9.2, 11.8.6, 11.7.11 Patch available CNA

Remediation

Upgrade Mattermost to 11.10.0, 11.9.2, 11.8.6 or 11.7.11, as described in Mattermost Advisory MMSA-2026-00723.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA Mattermost (Mattermost) Fixed in 11.10.0, 11.9.2, 11.8.6, 11.7.11

Timeline

  1. 2026-10-26 Threatist record created from CVE-2026-116516
  2. 2026-10-26 CISA SSVC decision points changed
  3. 2026-10-26 Priority changed: MEDIUM → LOW
  4. 2026-10-27 Alias added: GHSA-p4vm-rgr6-x9pc

References

Advisory 1

  • TI-2025-18933 Arbitrary file read in Mattermost Boards via import & export board archive CVSS 3.1CRITICAL 9.9
  • TI-2019-15071 An issue was discovered in Mattermost Packages before 5.16.3. CVSS 3.1CRITICAL 9.8
  • TI-2025-04465 Path Traversal Leading to RCE by Any Authenticated Mattermost User CVSS 3.1CRITICAL 9.9
  • TI-2019-15074 An issue was discovered in Mattermost Desktop App before 4.3.0 on macOS. CVSS 3.1CRITICAL 9.8
  • 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
See all 670 →

Sources

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