CVE-2026-6342

4.3 MEDIUM

Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to...

Published: 2026-05-18 · Last updated: 2026-05-29

Severity and scoring

CVSS: 4.3 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
CWE: CWE-863

Affected products

Vendor	Product
mattermost	mattermost_server

Description

Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to create subscriptions to groups that were not whitelisted via creating groups that share the same prefix as a whitelisted group. Mattermost Advisory ID: MMSA-2026-00601

Source: NVD

References

[NVD]https://nvd.nist.gov/vuln/detail/CVE-2026-6342
[Vendor advisory]https://mattermost.com/security-updates

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