Post actions can run playbook checklist task commands
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Tampering
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-352.
Summary
Mattermost versions 9.5.x <= 9.5.3, 9.6.x <= 9.6.1 and 8.1.x <= 8.1.12 fail to perform proper input validation on post actions which allows an attacker to run a playbook checklist task command as another user via creating and sharing a deceptive post action that unexpectedly runs a slash command in some arbitrary channel.
Why it matters now
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 | 9.5.0 – 9.5.3; 9.6.0 – 9.6.1; 8.1.0 – 8.1.12 | 9.7.0, 9.5.4, 9.6.2, 8.1.13 | Patch available | CNA |
- Mattermost VendorMattermost Affected 9.5.0 – 9.5.3; 9.6.0 – 9.6.1; 8.1.0 – 8.1.12 Fixed in 9.7.0, 9.5.4, 9.6.2, 8.1.13 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | 8.1.0 to before 8.1.13; 9.5.0 to before 9.5.4; 9.6.0 to before 9.6.2 | Vulnerable | Mattermost |
- cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions 8.1.0 to before 8.1.13; 9.5.0 to before 9.5.4; 9.6.0 to before 9.6.2 Vulnerable ·Mattermost
Remediation
- Fix · CNA Mattermost (Mattermost) Fixed in 9.7.0, 9.5.4, 9.6.2, 8.1.13
Timeline
- 2026-10-02 Threatist record created from CVE-2024-36255
References
Advisory 1
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
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences