CVE-2026-6957
Path traversal in Mattermost Legal Hold plugin via unsanitized file name from federated peer allows arbitrary file write.
- State
- Published
- Severity
- 8.0 High
- Published
- May 27, 2026
- Updated
- May 28, 2026
- Reserved
- Apr 24, 2026
Description
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
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 8.0 High | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H | Mattermost |
Weaknesses
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Products
| Product | Versions |
|---|---|
MattermostMattermost |
|
References
- MMSA-2026-00659vendor-advisory
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