GO-2026-6286
Mattermost doesn't restrict role_updated websocket event broadcasts to members of the affected team or channel in github.com/mattermost/mattermost-server
Quick fix
GO-2026-6286 — github.com/mattermost/mattermost-server: upgrade to the fixed version with the command below.
go get github.com/mattermost/mattermost-server@v10.11.17+incompatibleDetails
Mattermost doesn't restrict role_updated websocket event broadcasts to members of the affected team or channel in github.com/mattermost/mattermost-server
Are you affected?
Enter the version of the package you're using.
Affected packages
10.11.0+incompatible Fixed in: 10.11.17+incompatible go get github.com/mattermost/mattermost-server@v10.11.17+incompatible 0 No fixed version published yet for github.com/mattermost/mattermost-server/v5 (go modules). Pin to a known-safe version or switch to an alternative.
0 No fixed version published yet for github.com/mattermost/mattermost-server/v6 (go modules). Pin to a known-safe version or switch to an alternative.
8.0.0-20250731163400-5b955468ea1e Fixed in: 8.0.0-20260504071740-9408b98025d7 go get github.com/mattermost/mattermost/server/v8@v8.0.0-20260504071740-9408b98025d7 References
- https://github.com/advisories/GHSA-rp4v-qc77-phm4 [ADVISORY]
- https://nvd.nist.gov/vuln/detail/CVE-2026-3433 [ADVISORY]
- https://github.com/mattermost/mattermost/commit/0a0ab0d54d899d308bd1352cc577036917500318 [WEB]
- https://github.com/mattermost/mattermost/commit/7425c6817bf244f976c729f8a73cecac8039a1e1 [WEB]
- https://github.com/mattermost/mattermost/commit/9408b98025d7364d7dfe7cdb28fcd109b1b595a6 [WEB]
- https://github.com/mattermost/mattermost/commit/a30a331a29b9766d46716d4252056d7b74e66da0 [WEB]
- https://github.com/mattermost/mattermost/pull/35497 [WEB]
- https://github.com/mattermost/mattermost/pull/36256 [WEB]
- https://github.com/mattermost/mattermost/pull/36257 [WEB]
- https://github.com/mattermost/mattermost/pull/36341 [WEB]
- https://github.com/mattermost/mattermost/releases/tag/v10.11.16 [WEB]
- https://github.com/mattermost/mattermost/releases/tag/v11.5.5 [WEB]
- https://github.com/mattermost/mattermost/releases/tag/v11.6.2 [WEB]
- https://github.com/mattermost/mattermost/releases/tag/v11.7.0 [WEB]
- https://mattermost.com/security-updates [WEB]