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TI-2025-34764 Aliases CVE-2025-55074GHSA-9hh7-6558-qfp2

Channel member objects leak read status

Priority LOW 16CWE-1426Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub.

Summary

Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to enforce access permissions on the Agents plugin which allows other users to determine when users had read channels via channel member objects

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00182 7th percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): 11.0.0, 10.11.4, 10.5.12github.com/mattermost/mattermost-server (Go): 10.11.4, 10.5.12+1 more product

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
MattermostMattermost10.11.0 – 10.11.3; 10.5.0 – 10.5.1111.0.0, 10.11.4, 10.5.12Patch availableCNA
—github.com/mattermost/mattermost-server (Go)10.11.0 to before 10.11.410.11.4Patch availableGHSA-9hh7-6558-qfp2
—github.com/mattermost/mattermost-server (Go)10.5.0 to before 10.5.1210.5.12Patch availableGHSA-9hh7-6558-qfp2
—github.com/mattermost/mattermost/server/v8 (Go)before 8.0.0-20250905150616-ba86dfc5876b68.0.0-20250905150616-ba86dfc5876b6Patch availableGHSA-9hh7-6558-qfp2
  • Mattermost VendorMattermost Affected 10.11.0 – 10.11.3; 10.5.0 – 10.5.11 Fixed in 11.0.0, 10.11.4, 10.5.12 Patch available CNA
  • github.com/mattermost/mattermost-server (Go) Vendor— Affected 10.11.0 to before 10.11.4 Fixed in 10.11.4 Patch available GHSA-9hh7-6558-qfp2
  • github.com/mattermost/mattermost-server (Go) Vendor— Affected 10.5.0 to before 10.5.12 Fixed in 10.5.12 Patch available GHSA-9hh7-6558-qfp2
  • github.com/mattermost/mattermost/server/v8 (Go) Vendor— Affected before 8.0.0-20250905150616-ba86dfc5876b6 Fixed in 8.0.0-20250905150616-ba86dfc5876b6 Patch available GHSA-9hh7-6558-qfp2

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*10.5.0 to before 10.5.12; 10.11.0 to before 10.11.4VulnerableMattermost
  • cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions 10.5.0 to before 10.5.12; 10.11.0 to before 10.11.4 Vulnerable ·Mattermost

Remediation

  • Fix · CNA Mattermost (Mattermost) Fixed in 11.0.0, 10.11.4, 10.5.12
  • Fix · GHSA-9hh7-6558-qfp2 github.com/mattermost/mattermost-server (Go) Fixed in 10.11.4 Advisory →
  • Fix · GHSA-9hh7-6558-qfp2 github.com/mattermost/mattermost-server (Go) Fixed in 10.5.12 Advisory →
  • Fix · GHSA-9hh7-6558-qfp2 github.com/mattermost/mattermost/server/v8 (Go) Fixed in 8.0.0-20250905150616-ba86dfc5876b6 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-55074
  2. 2026-10-03 Alias added: GHSA-9hh7-6558-qfp2

References

Advisory 3

Other 6

  • 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