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TI-2026-04238 Aliases CVE-2026-4858GHSA-c4r7-j7pp-r8mp

Path traversal in integration action URL leading to arbitrary API execution via system admin’s auth token.

Priority MEDIUM 43CWE-22Published · Updated

Key facts

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

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

Summary

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to check integration URL for path traversal which allows an malicious authenticated user to call an arbitrary API via system admin Mattermost auth token using via path traversal in integration action URL.. Mattermost Advisory ID: MMSA-2026-00640

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00327 25th percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): 11.7.0, 11.6.1, 11.5.4 +2github.com/mattermost/mattermost-server (Go): 11.6.1, 11.5.4, 11.4.5 +1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MattermostMattermost11.6.0 – 11.6.0; 11.5.0 – 11.5.3; 11.4.0 – 11.4.4; 10.11.0 – 10.11.1411.7.0, 11.6.1, 11.5.4, 11.4.5, 10.11.15Patch availableCNA
—github.com/mattermost/mattermost-server (Go)11.6.0 to before 11.6.111.6.1Patch availableGHSA-c4r7-j7pp-r8mp
—github.com/mattermost/mattermost-server (Go)11.5.0 to before 11.5.411.5.4Patch availableGHSA-c4r7-j7pp-r8mp
—github.com/mattermost/mattermost-server (Go)11.4.0 to before 11.4.511.4.5Patch availableGHSA-c4r7-j7pp-r8mp
—github.com/mattermost/mattermost-server (Go)10.11.0 to before 10.11.1510.11.15Patch availableGHSA-c4r7-j7pp-r8mp
  • Mattermost VendorMattermost Affected 11.6.0 – 11.6.0; 11.5.0 – 11.5.3; 11.4.0 – 11.4.4; 10.11.0 – 10.11.14 Fixed in 11.7.0, 11.6.1, 11.5.4, 11.4.5, 10.11.15 Patch available CNA
  • github.com/mattermost/mattermost-server (Go) Vendor— Affected 11.6.0 to before 11.6.1 Fixed in 11.6.1 Patch available GHSA-c4r7-j7pp-r8mp
  • github.com/mattermost/mattermost-server (Go) Vendor— Affected 11.5.0 to before 11.5.4 Fixed in 11.5.4 Patch available GHSA-c4r7-j7pp-r8mp
  • github.com/mattermost/mattermost-server (Go) Vendor— Affected 11.4.0 to before 11.4.5 Fixed in 11.4.5 Patch available GHSA-c4r7-j7pp-r8mp
  • github.com/mattermost/mattermost-server (Go) Vendor— Affected 10.11.0 to before 10.11.15 Fixed in 10.11.15 Patch available GHSA-c4r7-j7pp-r8mp

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*10.11.0 to before 10.11.15; 11.4.0 to before 11.4.5; 11.5.0 to before 11.5.4VulnerableMattermost
cpe:2.3:a:mattermost:mattermost_server:11.6.0:*:*:*:*:*:*:*11.6.0VulnerableMattermost
  • cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions 10.11.0 to before 10.11.15; 11.4.0 to before 11.4.5; 11.5.0 to before 11.5.4 Vulnerable ·Mattermost
  • cpe:2.3:a:mattermost:mattermost_server:11.6.0:*:*:*:*:*:*:* Versions 11.6.0 Vulnerable ·Mattermost

Remediation

  • Fix · CNA Mattermost (Mattermost) Fixed in 11.7.0, 11.6.1, 11.5.4, 11.4.5, 10.11.15
  • Fix · GHSA-c4r7-j7pp-r8mp github.com/mattermost/mattermost-server (Go) Fixed in 11.6.1 Advisory →
  • Fix · GHSA-c4r7-j7pp-r8mp github.com/mattermost/mattermost-server (Go) Fixed in 11.5.4 Advisory →
  • Fix · GHSA-c4r7-j7pp-r8mp github.com/mattermost/mattermost-server (Go) Fixed in 11.4.5 Advisory →
  • Fix · GHSA-c4r7-j7pp-r8mp github.com/mattermost/mattermost-server (Go) Fixed in 10.11.15 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-4858
  2. 2026-10-03 Alias added: GHSA-c4r7-j7pp-r8mp

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