Path traversal in Mattermost
Priority LOW 37CWE-22Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
Mattermost Plugins versions <=1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via a malicious filename delivered through the shared-channel attachment sync protocol. Mattermost Advisory ID: MMSA-2026-00659
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00296 22nd percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): .0
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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mattermost | Mattermost | up to 1.1.5 | .0 | Patch available | CNA |
- Mattermost VendorMattermost Affected up to 1.1.5 Fixed in .0 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mattermost:legal_hold:*:*:*:*:*:mattermost:*:* | up to 1.1.5 | Vulnerable | Mattermost |
- cpe:2.3:a:mattermost:legal_hold:*:*:*:*:*:mattermost:*:* Versions up to 1.1.5 Vulnerable ·Mattermost
Remediation
- Fix · CNA Mattermost (Mattermost) Fixed in .0
Timeline
- 2026-10-02 Threatist record created from CVE-2026-6957
- 2026-10-03 Alias added: GHSA-x7w4-j7hv-94wg
References
Advisory 1
More Mattermost Legal Hold vulnerabilities
- TI-2026-03035 Authorization Bypass in Mattermost Legal Hold Plugin Due to Missing Return After Permission Check CVSS 3.1HIGH 8.3
Sources
- CVE-2026-6957 · CVE Program
- CVE-2026-6957 · NVD
- FIRST EPSS
- GHSA-x7w4-j7hv-94wg · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences