Read the docs
TI-2026-02090 Aliases CVE-2026-2461GHSA-hf8w-x9h5-5gf9

Missing authorization check allows unauthorized modification of other users' comments on a board

Priority LOW 19CWE-639Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-639.

Summary

Mattermost Plugins versions <=11.3 11.0.3 11.2.2 10.10.11.0 fail to implement authorisation checks on comment block modifications, which allows an authorised attacker with editor permission to modify comments created by other board members. Mattermost Advisory ID: MMSA-2025-00559

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00169 6th percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): 11.4.0, 11.3.1, 11.2.3 +1github.com/mattermost/mattermost-plugin-boards (Go): 0.0.0-20260108044135-57c5be5b6ef5

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 11.0.3; up to 11.2.2; up to 10.10.1111.4.0, 11.3.1, 11.2.3, 10.11.11Patch availableCNA
—github.com/mattermost/mattermost-plugin-boards (Go)before 0.0.0-20260108044135-57c5be5b6ef50.0.0-20260108044135-57c5be5b6ef5Patch availableGHSA-hf8w-x9h5-5gf9
  • Mattermost VendorMattermost Affected up to 11.0.3; up to 11.2.2; up to 10.10.11 Fixed in 11.4.0, 11.3.1, 11.2.3, 10.11.11 Patch available CNA
  • github.com/mattermost/mattermost-plugin-boards (Go) Vendor— Affected before 0.0.0-20260108044135-57c5be5b6ef5 Fixed in 0.0.0-20260108044135-57c5be5b6ef5 Patch available GHSA-hf8w-x9h5-5gf9

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*before 10.11.11; 11.0.0 – 11.0.3; 11.1.0 to before 11.2.3; 11.3.0 to before 11.3.1VulnerableMattermost
  • cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions before 10.11.11; 11.0.0 – 11.0.3; 11.1.0 to before 11.2.3; 11.3.0 to before 11.3.1 Vulnerable ·Mattermost

Remediation

  • Fix · CNA Mattermost (Mattermost) Fixed in 11.4.0, 11.3.1, 11.2.3, 10.11.11
  • Fix · GHSA-hf8w-x9h5-5gf9 github.com/mattermost/mattermost-plugin-boards (Go) Fixed in 0.0.0-20260108044135-57c5be5b6ef5 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-2461
  2. 2026-10-03 Alias added: GHSA-hf8w-x9h5-5gf9

References

Advisory 2

Other 2

  • 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