CVE-2026-6957
BaseFortify
Publication date: 2026-05-27
Last updated on: 2026-05-27
Assigner: Mattermost, Inc.
Description
Description
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| mattermost | plugins | to 1.1.5 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-22 | The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in Mattermost Plugins versions up to 1.1.5, where the software fails to properly sanitize filenames received from federated peers before using them to create export destination paths.
Because of this, an administrator of a remote federated Mattermost server can exploit this flaw by sending a malicious filename through the shared-channel attachment sync protocol.
This allows the attacker to write files to arbitrary locations within the target server's filestore.
How can this vulnerability impact me? :
The vulnerability can have severe impacts because it allows an attacker with administrative access on a federated Mattermost server to write files anywhere within the target server's filestore.
This can lead to complete compromise of the target system's confidentiality, integrity, and availability.
- Confidentiality impact: The attacker can potentially overwrite or add files, exposing sensitive data.
- Integrity impact: The attacker can modify or replace files, potentially injecting malicious code or corrupting data.
- Availability impact: The attacker could disrupt normal operations by overwriting critical files.