Improper check for unusual conditions in Mattermost
Priority LOW 21CWE-754Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.
Summary
Mattermost versions 9.6.0, 9.5.x before 9.5.3, 9.4.x before 9.4.5, and 8.1.x before 8.1.12 fail to handle JSON parsing errors in custom status values, which allows an authenticated attacker to crash other users' web clients via a malformed custom status.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00552 46th percentileScored 2026-11-07
Fix Partial Mattermost (Mattermost): 9.7.0, 9.6.1, 9.5.3 +2github.com/mattermost/mattermost-server (Go): 8.1.12, 9.4.5, 9.5.3 +1Red 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; 9.4.0 – 9.4.4; 8.1.0 – 8.1.11 | 9.7.0, 9.6.1, 9.5.3, 9.4.5, 8.1.12 | Patch available | CNA |
| — | github.com/mattermost/mattermost-server (Go) | 8.1.0 to before 8.1.12 | 8.1.12 | Patch available | GHSA-8f99-g2pj-x8w3 |
| — | github.com/mattermost/mattermost-server (Go) | 9.4.0 to before 9.4.5 | 9.4.5 | Patch available | GHSA-8f99-g2pj-x8w3 |
| — | github.com/mattermost/mattermost-server (Go) | 9.5.0 to before 9.5.3 | 9.5.3 | Patch available | GHSA-8f99-g2pj-x8w3 |
| — | github.com/mattermost/mattermost-server (Go) | 9.6.0-rc1 to before 9.6.1 | 9.6.1 | Patch available | GHSA-8f99-g2pj-x8w3 |
- Mattermost VendorMattermost Affected 9.6.0; 9.5.0 – 9.5.2; 9.4.0 – 9.4.4; 8.1.0 – 8.1.11 Fixed in 9.7.0, 9.6.1, 9.5.3, 9.4.5, 8.1.12 Patch available CNA
- github.com/mattermost/mattermost-server (Go) Vendor— Affected 8.1.0 to before 8.1.12 Fixed in 8.1.12 Patch available GHSA-8f99-g2pj-x8w3
- github.com/mattermost/mattermost-server (Go) Vendor— Affected 9.4.0 to before 9.4.5 Fixed in 9.4.5 Patch available GHSA-8f99-g2pj-x8w3
- github.com/mattermost/mattermost-server (Go) Vendor— Affected 9.5.0 to before 9.5.3 Fixed in 9.5.3 Patch available GHSA-8f99-g2pj-x8w3
- 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-8f99-g2pj-x8w3
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | 8.1.0 to before 8.1.12; 9.4.0 to before 9.4.5; 9.5.0 to before 9.5.3; 9.6.0 to before 9.6.1 | Vulnerable | Mattermost |
- cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions 8.1.0 to before 8.1.12; 9.4.0 to before 9.4.5; 9.5.0 to before 9.5.3; 9.6.0 to before 9.6.1 Vulnerable ·Mattermost
Remediation
- Fix · CNA Mattermost (Mattermost) Fixed in 9.7.0, 9.6.1, 9.5.3, 9.4.5, 8.1.12
- Fix · GHSA-8f99-g2pj-x8w3 github.com/mattermost/mattermost-server (Go) Fixed in 8.1.12 Advisory →
- Fix · GHSA-8f99-g2pj-x8w3 github.com/mattermost/mattermost-server (Go) Fixed in 9.4.5 Advisory →
- Fix · GHSA-8f99-g2pj-x8w3 github.com/mattermost/mattermost-server (Go) Fixed in 9.5.3 Advisory →
- Fix · GHSA-8f99-g2pj-x8w3 github.com/mattermost/mattermost-server (Go) Fixed in 9.6.1 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-2024-4182
- 2026-10-03 Alias added: GHSA-8f99-g2pj-x8w3
References
Other 5
- https://github.com/mattermost/mattermost/commit/41333a0babf565453d89287549bec1e546e75ce7
- https://github.com/mattermost/mattermost/commit/6cbab0f7ece104681f73dd12c75d9f22d567125e
- https://github.com/mattermost/mattermost/commit/a99dadd80c57d376185ca06f8f70919a6f135bc6
- https://github.com/mattermost/mattermost/commit/f84f8ed65f6a5faba974426424b684635455a527
- 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-2024-4182 · CVE Program
- CVE-2024-4182 · NVD
- FIRST EPSS
- GHSA-8f99-g2pj-x8w3 · GitHub Advisory Database · CC BY 4.0
- CVE-2024-4182 · 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