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
Metrics
Affected Vendors & Products
References
| Link | Providers |
|---|---|
| https://mattermost.com/security-updates |
|
History
Tue, 02 Jun 2026 14:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Mattermost legal Hold
|
|
| CPEs | cpe:2.3:a:mattermost:legal_hold:*:*:*:*:*:mattermost:*:* | |
| Vendors & Products |
Mattermost legal Hold
|
Thu, 28 May 2026 04:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Mattermost
Mattermost mattermost |
|
| Vendors & Products |
Mattermost
Mattermost mattermost |
Wed, 27 May 2026 18:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Wed, 27 May 2026 15:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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 | |
| Title | Path traversal in Mattermost Legal Hold plugin via unsanitized file name from federated peer allows arbitrary file write. | |
| Weaknesses | CWE-22 | |
| References |
| |
| Metrics |
cvssV3_1
|
Status: PUBLISHED
Assigner: Mattermost
Published: 2026-05-27T14:23:50.770Z
Updated: 2026-05-28T03:55:34.437Z
Reserved: 2026-04-24T13:23:50.185Z
Link: CVE-2026-6957
Updated: 2026-05-27T17:26:56.583Z
Status : Analyzed
Published: 2026-05-27T15:16:34.903
Modified: 2026-06-02T14:29:03.550
Link: CVE-2026-6957
No data.