Description
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
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mattermost | Mattermost | 11.5.0 – ≤ 11.5.1, 10.11.0 – ≤ 10.11.13 | 11.6.0 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 | openSUSE-SU-2026:21483-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | < 5.3.2-0.20260310115442-5a1ea95044dc | 5.3.2-0.20260310115442-5a1ea95044dc | GHSA-jx93-pf6x-874r |
| 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 | — | GO-2026-5484 |
| Go | github.com/mattermost/mattermost-server/v6 | all versions | — | GO-2026-5484 |
| 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/v8 | all versions | — | GO-2026-5484 |
Advisories 1
- openSUSE-SU-2026:21483-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Jul 31, 2026
References
- MMSA-2026-00622 vendor-advisory