CVSS 3.1
3.8 lowCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:LCVE-2026-8823
Low (3.8) in mattermost mattermost server. EPSS 0.3% chance of exploitation in the next 30 days. Fixed in github.com/mattermost/mattermost-server 10.11.18, 10.11.18+incompatible, 11.7.1.
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
Severity
- EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 24% of CVEs (scores of 2026-10-31)
- CWE
- CWE-863
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mattermost:mattermost_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-xmfh-3ccg-c9fx | Go | github.com/mattermost/mattermost-server | >=11.7.0 <11.7.1 | 11.7.1 |
| GHSA-xmfh-3ccg-c9fx | Go | github.com/mattermost/mattermost-server | >=10.11.0 <10.11.18 | 10.11.18 |
| GHSA-xmfh-3ccg-c9fx | Go | github.com/mattermost/mattermost/server/v8 | <8.0.0-20260518160100-9bd77d3fc4d2 | 8.0.0-20260518160100-9bd77d3fc4d2 |
| GO-2026-6547 | Go | github.com/mattermost/mattermost-server | >=10.11.0+incompatible <10.11.18+incompatible >=11.7.0+incompatible <11.7.1+incompatible | 10.11.18+incompatible, 11.7.1+incompatible |
| GO-2026-6547 | Go | github.com/mattermost/mattermost-server/v5 | all versions | no fix published |
| GO-2026-6547 | Go | github.com/mattermost/mattermost-server/v6 | all versions | no fix published |
| GO-2026-6547 | Go | github.com/mattermost/mattermost/server/v8 | <8.0.0-20260518160100-9bd77d3fc4d2 | 8.0.0-20260518160100-9bd77d3fc4d2 |