CVSS 3.1
9.9 criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HCVE-2026-4858
Critical (9.9) in mattermost mattermost server. EPSS 0.3% chance of exploitation in the next 30 days. Fixed in github.com/mattermost/mattermost-server 10.11.15, 10.11.15+incompatible, 11.4.5.
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to check integration URL for path traversal which allows an malicious authenticated user to call an arbitrary API via system admin Mattermost auth token using via path traversal in integration action URL.. Mattermost Advisory ID: MMSA-2026-00640
Severity
- EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 25% of CVEs (scores of 2026-10-31)
- CWE
- CWE-22
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mattermost:mattermost_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-c4r7-j7pp-r8mp | Go | github.com/mattermost/mattermost-server | >=11.6.0 <11.6.1 | 11.6.1 |
| GHSA-c4r7-j7pp-r8mp | Go | github.com/mattermost/mattermost-server | >=11.5.0 <11.5.4 | 11.5.4 |
| GHSA-c4r7-j7pp-r8mp | Go | github.com/mattermost/mattermost-server | >=11.4.0 <11.4.5 | 11.4.5 |
| GHSA-c4r7-j7pp-r8mp | Go | github.com/mattermost/mattermost-server | >=10.11.0 <10.11.15 | 10.11.15 |
| GO-2026-5311 | Go | github.com/mattermost/mattermost-server | >=10.11.0+incompatible <10.11.15+incompatible >=11.4.0+incompatible <11.4.5+incompatible >=11.5.0+incompatible <11.5.4+incompatible >=11.6.0+incompatible <11.6.1+incompatible | 10.11.15+incompatible, 11.4.5+incompatible, 11.5.4+incompatible, 11.6.1+incompatible |