cvedb.io
CVE-2026-4274
MEDIUM · CVSS 5.4
EPSS exploitation probability: 0%
Published 2026-03-26T11:16:21.257 · Last modified 2026-06-17T10:56:20.560

Summary

Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared channel via sending crafted membership sync messages that trigger team membership assignment. Mattermost Advisory ID: MMSA-2026-00574

Affected products

mattermost — mattermost_server

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.