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TI-2026-18380 Aliases CVE-2026-22892GHSA-9pj7-jh2r-87g8

Insufficient Authorization in Mattermost Jira Plugin Allows Unauthorized Access to Post Attachments

Priority LOW 20CWE-863Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-863.

Summary

Mattermost versions 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 11.2.1 fail to validate user permissions when creating Jira issues from Mattermost posts, which allows an authenticated attacker with access to the Jira plugin to read post content and attachments from channels they do not have access to via the /create-issue API endpoint by providing the post ID of an inaccessible post.. Mattermost Advisory ID: MMSA-2025-00550

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00269 19th percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): 11.3.0, 11.1.3, 10.11.10 +1github.com/mattermost/mattermost-server (Go): 11.2.2, 11.1.3, 10.11.10

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
MattermostMattermost11.1.0 – 11.1.2; 10.11.0 – 10.11.9; 11.2.0 – 11.2.111.3.0, 11.1.3, 10.11.10, 11.2.2Patch availableCNA
—github.com/mattermost/mattermost-server (Go)11.2.0 to before 11.2.211.2.2Patch availableGHSA-9pj7-jh2r-87g8
—github.com/mattermost/mattermost-server (Go)11.1.0 to before 11.1.311.1.3Patch availableGHSA-9pj7-jh2r-87g8
—github.com/mattermost/mattermost-server (Go)10.11.0 to before 10.11.1010.11.10Patch availableGHSA-9pj7-jh2r-87g8
  • Mattermost VendorMattermost Affected 11.1.0 – 11.1.2; 10.11.0 – 10.11.9; 11.2.0 – 11.2.1 Fixed in 11.3.0, 11.1.3, 10.11.10, 11.2.2 Patch available CNA
  • github.com/mattermost/mattermost-server (Go) Vendor— Affected 11.2.0 to before 11.2.2 Fixed in 11.2.2 Patch available GHSA-9pj7-jh2r-87g8
  • github.com/mattermost/mattermost-server (Go) Vendor— Affected 11.1.0 to before 11.1.3 Fixed in 11.1.3 Patch available GHSA-9pj7-jh2r-87g8
  • github.com/mattermost/mattermost-server (Go) Vendor— Affected 10.11.0 to before 10.11.10 Fixed in 10.11.10 Patch available GHSA-9pj7-jh2r-87g8

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*10.11.0 to before 10.11.10; 11.0.0 to before 11.1.3; 11.2.0 to before 11.2.2VulnerableMattermost
  • cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions 10.11.0 to before 10.11.10; 11.0.0 to before 11.1.3; 11.2.0 to before 11.2.2 Vulnerable ·Mattermost

Remediation

  • Fix · CNA Mattermost (Mattermost) Fixed in 11.3.0, 11.1.3, 10.11.10, 11.2.2
  • Fix · GHSA-9pj7-jh2r-87g8 github.com/mattermost/mattermost-server (Go) Fixed in 11.2.2 Advisory →
  • Fix · GHSA-9pj7-jh2r-87g8 github.com/mattermost/mattermost-server (Go) Fixed in 11.1.3 Advisory →
  • Fix · GHSA-9pj7-jh2r-87g8 github.com/mattermost/mattermost-server (Go) Fixed in 10.11.10 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-22892
  2. 2026-10-03 Alias added: GHSA-9pj7-jh2r-87g8

References

Advisory 2

Other 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