Mattermost fails to scope role_updated websocket events to authorized team and channel members

Publishers link these advisories through the identifiers shown below. A shared identifier or date alone does not tell you whether your software is affected or whether the advisories describe the same cause.

CVE-2026-3433 · CVE overview and exploitation status

EUVD-2026-36498

GHSA-rp4v-qc77-phm4

GO-2026-6286

cve-program · CVE-2026-3433

• https://mattermost.com/security-updates

euvd · EUVD-2026-36498

• https://mattermost.com/security-updates

nvd · CVE-2026-3433

• https://mattermost.com/security-updates

osv · GHSA-rp4v-qc77-phm4

• https://nvd.nist.gov/vuln/detail/CVE-2026-3433
• https://github.com/mattermost/mattermost/pull/35497
• https://github.com/mattermost/mattermost/pull/36256
• https://github.com/mattermost/mattermost/pull/36257
• https://github.com/mattermost/mattermost/pull/36341
• https://github.com/mattermost/mattermost/commit/0a0ab0d54d899d308bd1352cc577036917500318
• https://github.com/mattermost/mattermost/commit/7425c6817bf244f976c729f8a73cecac8039a1e1
• https://github.com/mattermost/mattermost/commit/9408b98025d7364d7dfe7cdb28fcd109b1b595a6
• https://github.com/mattermost/mattermost/commit/a30a331a29b9766d46716d4252056d7b74e66da0
• https://github.com/mattermost/mattermost
• https://github.com/mattermost/mattermost/releases/tag/v10.11.16
• https://github.com/mattermost/mattermost/releases/tag/v11.5.5
• https://github.com/mattermost/mattermost/releases/tag/v11.6.2
• https://github.com/mattermost/mattermost/releases/tag/v11.7.0
• https://mattermost.com/security-updates

osv · GO-2026-6286

• https://github.com/advisories/GHSA-rp4v-qc77-phm4
• https://nvd.nist.gov/vuln/detail/CVE-2026-3433
• https://github.com/mattermost/mattermost/commit/0a0ab0d54d899d308bd1352cc577036917500318
• https://github.com/mattermost/mattermost/commit/7425c6817bf244f976c729f8a73cecac8039a1e1
• https://github.com/mattermost/mattermost/commit/9408b98025d7364d7dfe7cdb28fcd109b1b595a6
• https://github.com/mattermost/mattermost/commit/a30a331a29b9766d46716d4252056d7b74e66da0
• https://github.com/mattermost/mattermost/pull/35497
• https://github.com/mattermost/mattermost/pull/36256
• https://github.com/mattermost/mattermost/pull/36257
• https://github.com/mattermost/mattermost/pull/36341
• https://github.com/mattermost/mattermost/releases/tag/v10.11.16
• https://github.com/mattermost/mattermost/releases/tag/v11.5.5
• https://github.com/mattermost/mattermost/releases/tag/v11.6.2
• https://github.com/mattermost/mattermost/releases/tag/v11.7.0
• https://mattermost.com/security-updates

• Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to restrict role_updated websocket event broadcasts to members of the affected team or channel which allows an authenticated attacker with… · Advisory content revised · 15 Nov 2026