CVE-2026-3495
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to escape some variables that could contain malicious content during error page composition which allows an attacker with access to edit some site configuration to execute some malicious code via injecting some JS as part of those values.. Mattermost Advisory ID: MMSA-2026-00622
- CVSS 3.1
- 4.8
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - EPSS
- 0.1% chance of exploitation in the next 30 days; higher than 3% of CVEs (scores of 2026-10-25)
- CWE
- CWE-79
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mattermost:mattermost_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-jx93-pf6x-874r | Go | github.com/mattermost/mattermost/server/v8 | >=10.11.0 <10.11.14 | 10.11.14 |
| GHSA-jx93-pf6x-874r | Go | github.com/mattermost/mattermost/server/v8 | >=11.5.0 <11.5.2 | 11.5.2 |
| GHSA-jx93-pf6x-874r | Go | github.com/mattermost/mattermost/server/v8 | <8.0.0-20260310115442-5a1ea95044d | 8.0.0-20260310115442-5a1ea95044d |
| GHSA-jx93-pf6x-874r | Go | github.com/mattermost/mattermost-server | <5.3.2-0.20260310115442-5a1ea95044dc | 5.3.2-0.20260310115442-5a1ea95044dc |
| GO-2026-5484 | Go | github.com/mattermost/mattermost-server | >=10.11.0+incompatible <10.11.14+incompatible >=11.5.0+incompatible <11.5.2+incompatible | 10.11.14+incompatible, 11.5.2+incompatible |
| GO-2026-5484 | Go | github.com/mattermost/mattermost-server/v5 | all versions | no fix published |
| GO-2026-5484 | Go | github.com/mattermost/mattermost-server/v6 | all versions | no fix published |
| GO-2026-5484 | Go | github.com/mattermost/mattermost/server/v8 | all versions | no fix published |