LOW3.8
GHSA-xmfh-3ccg-c9fx
Mattermost has an Incorrect Authorization issue
Quick fix
GHSA-xmfh-3ccg-c9fx — github.com/mattermost/mattermost-server: upgrade to the fixed version with the command below.
go get github.com/mattermost/mattermost-server@v11.7.1Details
Mattermost versions 11.7.x <= 11.7.0, 10.11.x <= 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-privileged administrator to degrade arbitrary bot accounts via the standard demote-user API.. Mattermost Advisory ID: MMSA-2026-00669
Are you affected?
Enter the version of the package you're using.
Affected packages
Go/github.com/mattermost/mattermost-server
Introduced in:
11.7.0Fixed in: 11.7.1Fix
go get github.com/mattermost/mattermost-server@v11.7.1Go/github.com/mattermost/mattermost-server
Introduced in:
10.11.0Fixed in: 10.11.18Fix
go get github.com/mattermost/mattermost-server@v10.11.18Go/github.com/mattermost/mattermost/server/v8
Introduced in:
0Fixed in: 8.0.0-20260518160100-9bd77d3fc4d2Fix
go get github.com/mattermost/mattermost/server/v8@v8.0.0-20260518160100-9bd77d3fc4d2References
- https://nvd.nist.gov/vuln/detail/CVE-2026-8823[ADVISORY]
- https://github.com/mattermost/mattermost/pull/36487[WEB]
- https://github.com/mattermost/mattermost/commit/7972fc53f5c0b0175879a9737308a87b42db1f0b[WEB]
- https://github.com/mattermost/mattermost/commit/9bd77d3fc4d2af3f7f0259a205174e76a1a276e1[WEB]
- https://github.com/mattermost/mattermost/commit/c9bf3609fb9a3e5c2de94c50742c9b91fd723e3d[WEB]
- https://github.com/mattermost/mattermost/commit/d9a55e394cd5bc15edb49e9606bec8fec03ac4c6[WEB]
- https://docs.mattermost.com/security-guide/security-updates[WEB]
- https://github.com/mattermost/mattermost[PACKAGE]
- https://github.com/mattermost/mattermost/releases/tag/v10.11.18[WEB]
- https://github.com/mattermost/mattermost/releases/tag/v11.7.1[WEB]