Go/github.com/mattermost/mattermost-server CVE-2026-4265: unknown, EPSS 0.38%
Mattermost fails to validate team-specific upload_file permissions in github.com/mattermost/mattermost-server
Action: Upgrade github.com/mattermost/mattermost-server to 10.11.11+incompatible or later.
go get github.com/mattermost/mattermost-server@v10.11.11+incompatiblego get github.com/mattermost/mattermost-server@v11.2.3+incompatiblego get github.com/mattermost/mattermost-server@v11.3.1+incompatibleAffected
| introduced | fixed | last affected |
|---|---|---|
| 10.11.0-rc1+incompatible | 10.11.11+incompatible | - |
| 11.2.0-rc1+incompatible | 11.2.3+incompatible | - |
| 11.3.0-rc1+incompatible | 11.3.1+incompatible | - |
Fixed versions
| 10.11.11+incompatible | 11.2.3+incompatible | 11.3.1+incompatible |
Sources
- osv: GO-2026-4749
- https://github.com/advisories/GHSA-xpvf-6qcc-9jqc
- https://nvd.nist.gov/vuln/detail/CVE-2026-4265
- https://github.com/mattermost/mattermost/commit/c7f6efdfb035490f494b3177996ee5f4b278c988
- https://mattermost.com/security-updates
CVE-2026-4265 · published · modified · JSON