CVE-2025-6465
Path traversal in image upload with preview overwrite
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Path traversal in image upload with preview overwrite
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.
- Record
CVE-2025-6465- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
EUVDEUVD-2025-25460
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.
- Record
EUVD-2025-25460- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-pj6f-rc94-gw53
Mattermost Fails to Sanitize File Names
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.
- Record
GHSA-pj6f-rc94-gw53- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
NVD
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.
- Record
CVE-2025-6465- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
OSV
Path traversal in image upload with preview overwrite
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.
- Record
CVE-2025-6465- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-22
- Updated
- 2026-11-07
OSVGHSA-pj6f-rc94-gw53
Mattermost Fails to Sanitize File Names
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.
- Record
GHSA-pj6f-rc94-gw53- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
OSVGO-2025-3910 No score
Mattermost Fails to Sanitize File Names in github.com/mattermost/mattermost-server
Mattermost Fails to Sanitize File Names in github.com/mattermost/mattermost-server.
NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions.
(If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.)
The additional affected modules and versions are: github.com/mattermost/mattermost/server/v8 before v8.0.0-20250708173752-d6b35c41f0ae5.
- Record
GO-2025-3910- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/mattermost/mattermost-serverGo |
10.8.0 to 10.8.3 | 10.8.4 |
github.com/mattermost/mattermost-serverGo |
10.5.0 to 10.5.8 | 10.5.9 |
github.com/mattermost/mattermost-serverGo |
10.9.0 to 10.9.3 | 10.9.4 |
github.com/mattermost/mattermost-serverGo |
10.10.0 to 10.10.0 | 10.10.1 |
github.com/mattermost/mattermost/server/v8Go |
before 8.0.0-20250708173752-d6b35c41f0ae5 | 8.0.0-20250708173752-d6b35c41f0ae5 |
github.com/mattermost/mattermost-serverGo |
10.8.0 up to 10.8.4 | 10.8.4 |
github.com/mattermost/mattermost-serverGo |
10.5.0 up to 10.5.9 | 10.5.9 |
github.com/mattermost/mattermost-serverGo |
10.9.0 up to 10.9.4 | 10.9.4 |
github.com/mattermost/mattermost-serverGo |
10.10.0 up to 10.10.1 | 10.10.1 |
github.com/mattermost/mattermost-serverGo |
10.5.0+incompatible up to 10.5.9+incompatible, 10.8.0+incompatible up to 10.8.4+incompatible, 10.9.0+incompatible up to 10.9.4+incompatible, 10.10.0+incompatible up to 10.10.1+incompatible | 10.5.9+incompatible10.8.4+incompatible10.9.4+incompatible10.10.1+incompatible |
github.com/mattermost/mattermost-server/v5Go |
All versions | None known |
github.com/mattermost/mattermost-server/v6Go |
All versions | None known |
github.com/mattermost/mattermost/server/v8Go |
All versions | None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-6465 is a medium vulnerability (CVSS 4.3) in Mattermost, published August 21, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.77%, the 55th percentile. Fixed in github.com/mattermost/mattermost-server 10.8.4.