Go/github.com/mattermost/mattermost/server/v8 CVE-2026-6339: medium 4.3, EPSS 0.11%
Mattermost doesn't validate the X-Requested-With header on the burn-on-read reveal endpoint in github.com/mattermost/mattermost-server
Action: Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20260327001745-7a339a6438f5 or later.
go get github.com/mattermost/mattermost/server/v8@v8.0.0-20260327001745-7a339a6438f5Affected
| introduced | fixed | last affected |
|---|---|---|
| 0 | 8.0.0-20260327001745-7a339a6438f5 | - |
Fixed versions
| 8.0.0-20260327001745-7a339a6438f5 |
Sources
- osv: GO-2026-5769#Go/github.com/mattermost/mattermost/server/v8
- nvd: CVE-2026-6339
- https://github.com/advisories/GHSA-xvcx-mgpc-5xh3
- https://github.com/mattermost/mattermost/commit/7a339a6438f5a4a5feba6b8de887f17a1378b207
- https://mattermost.com/security-updates
CVE-2026-6339 · published · modified · JSON