Improper access control in Mattermost
Priority LOW 14CWE-284Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-284.
Summary
Mattermost versions 9.6.0, 9.5.x before 9.5.3, and 8.1.x before 8.1.12 fail to fully validate role changes which allows an attacker authenticated as team admin to demote users to guest via crafted HTTP requests.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00502 43rd percentileScored 2026-11-07
Fix Partial Mattermost (Mattermost): 9.7.0, 9.6.1, 9.5.3 +1github.com/mattermost/mattermost-server (Go): 9.6.1, 9.5.3, 8.1.12Red Hat: 2 without a fix
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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mattermost | Mattermost | 9.6.0; 9.5.0 – 9.5.2; 8.1.0 – 8.1.11 | 9.7.0, 9.6.1, 9.5.3, 8.1.12 | Patch available | CNA |
| — | github.com/mattermost/mattermost-server (Go) | 9.6.0-rc1 to before 9.6.1 | 9.6.1 | Patch available | GHSA-5qx9-9ffj-5r8f |
| — | github.com/mattermost/mattermost-server (Go) | 9.5.0 to before 9.5.3 | 9.5.3 | Patch available | GHSA-5qx9-9ffj-5r8f |
| — | github.com/mattermost/mattermost-server (Go) | 8.1.0 to before 8.1.12 | 8.1.12 | Patch available | GHSA-5qx9-9ffj-5r8f |
- Mattermost VendorMattermost Affected 9.6.0; 9.5.0 – 9.5.2; 8.1.0 – 8.1.11 Fixed in 9.7.0, 9.6.1, 9.5.3, 8.1.12 Patch available CNA
- github.com/mattermost/mattermost-server (Go) Vendor— Affected 9.6.0-rc1 to before 9.6.1 Fixed in 9.6.1 Patch available GHSA-5qx9-9ffj-5r8f
- github.com/mattermost/mattermost-server (Go) Vendor— Affected 9.5.0 to before 9.5.3 Fixed in 9.5.3 Patch available GHSA-5qx9-9ffj-5r8f
- github.com/mattermost/mattermost-server (Go) Vendor— Affected 8.1.0 to before 8.1.12 Fixed in 8.1.12 Patch available GHSA-5qx9-9ffj-5r8f
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | 8.1.0 to before 8.1.12; 9.5.0 to before 9.5.3 | Vulnerable | Mattermost |
| cpe:2.3:a:mattermost:mattermost_server:9.6.0:-:*:*:*:*:*:* | 9.6.0 | Vulnerable | Mattermost |
| cpe:2.3:a:mattermost:mattermost_server:9.6.0:rc1:*:*:*:*:*:* | 9.6.0 rc1 | Vulnerable | Mattermost |
| cpe:2.3:a:mattermost:mattermost_server:9.6.0:rc2:*:*:*:*:*:* | 9.6.0 rc2 | Vulnerable | Mattermost |
| cpe:2.3:a:mattermost:mattermost_server:9.6.0:rc3:*:*:*:*:*:* | 9.6.0 rc3 | Vulnerable | Mattermost |
- cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions 8.1.0 to before 8.1.12; 9.5.0 to before 9.5.3 Vulnerable ·Mattermost
- cpe:2.3:a:mattermost:mattermost_server:9.6.0:-:*:*:*:*:*:* Versions 9.6.0 Vulnerable ·Mattermost
- cpe:2.3:a:mattermost:mattermost_server:9.6.0:rc1:*:*:*:*:*:* Versions 9.6.0 rc1 Vulnerable ·Mattermost
- cpe:2.3:a:mattermost:mattermost_server:9.6.0:rc2:*:*:*:*:*:* Versions 9.6.0 rc2 Vulnerable ·Mattermost
- cpe:2.3:a:mattermost:mattermost_server:9.6.0:rc3:*:*:*:*:*:* Versions 9.6.0 rc3 Vulnerable ·Mattermost
Remediation
- Fix · CNA Mattermost (Mattermost) Fixed in 9.7.0, 9.6.1, 9.5.3, 8.1.12
- Fix · GHSA-5qx9-9ffj-5r8f github.com/mattermost/mattermost-server (Go) Fixed in 9.6.1 Advisory →
- Fix · GHSA-5qx9-9ffj-5r8f github.com/mattermost/mattermost-server (Go) Fixed in 9.5.3 Advisory →
- Fix · GHSA-5qx9-9ffj-5r8f github.com/mattermost/mattermost-server (Go) Fixed in 8.1.12 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Advanced Cluster Management for Kubernetes 2 | Affected | No fix yet: Fix deferred |
| Red Hat Advanced Cluster Security 3 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-02 Threatist record created from CVE-2024-4198
- 2026-10-03 Alias added: GHSA-5qx9-9ffj-5r8f
References
Other 4
- https://github.com/mattermost/mattermost/commit/3d6d8a7c1f7105558fe266a1b379859a4dba4e9b
- https://github.com/mattermost/mattermost/commit/408ce4a82bb55ce27801f7044d9b3b49e82c47ed
- https://github.com/mattermost/mattermost/commit/fba5b8e348feada9b21290369c3598ccd5c04424
- https://github.com/mattermost/mattermost
More Mattermost Server vulnerabilities
- 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
Sources
- CVE-2024-4198 · CVE Program
- CVE-2024-4198 · NVD
- FIRST EPSS
- GHSA-5qx9-9ffj-5r8f · GitHub Advisory Database · CC BY 4.0
- CVE-2024-4198 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences