CVE-2026-3637
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627
- CVSS 3.1
- 4.3
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 4% of CVEs (scores of 2026-10-25)
- CWE
- CWE-862
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mattermost:mattermost_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-v549-xx3c-6pc8 | Go | github.com/mattermost/mattermost/server/v8 | >=10.11.0 <10.11.14 | 10.11.14 |
| GHSA-v549-xx3c-6pc8 | Go | github.com/mattermost/mattermost/server/v8 | >=11.4.0 <11.4.4 | 11.4.4 |
| GHSA-v549-xx3c-6pc8 | Go | github.com/mattermost/mattermost/server/v8 | <8.0.0-20260316171743-090408f09f53 | 8.0.0-20260316171743-090408f09f53 |
| GHSA-v549-xx3c-6pc8 | Go | github.com/mattermost/mattermost/server/v8 | >=11.5.0 <11.5.2 | 11.5.2 |
| GHSA-v549-xx3c-6pc8 | Go | github.com/mattermost/mattermost-server | <5.3.2-0.20260316171743-090408f09f53 | 5.3.2-0.20260316171743-090408f09f53 |
| GO-2026-5651 | Go | github.com/mattermost/mattermost-server | >=10.11.0+incompatible <10.11.14+incompatible >=11.4.0+incompatible <11.4.4+incompatible >=11.5.0+incompatible <11.5.2+incompatible | 10.11.14+incompatible, 11.4.4+incompatible, 11.5.2+incompatible |
| GO-2026-5651 | Go | github.com/mattermost/mattermost-server/v5 | all versions | no fix published |
| GO-2026-5651 | Go | github.com/mattermost/mattermost-server/v6 | all versions | no fix published |
| GO-2026-5651 | Go | github.com/mattermost/mattermost/server/v8 | <8.0.0-20260316171743-090408f09f53 | 8.0.0-20260316171743-090408f09f53 |