CVE-2026-45266: Nextcloud: Unauthorized force-mute from missing permission check when using internal signaling

Severity: low (CVSS 3.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-01 · updated 2026-07-22
Weakness: CWE-284

Description

Nextcloud is an open source content collaboration platform. Prior to versions 21.1.10, 22.0.11, and 23.0.3, a low-privileged user can force other user's microphones to be muted in calls when no High-performance Backend is installed. This issue has been patched in versions 21.1.10, 22.0.11, and 23.0.3.

Affected products

nextcloud security-advisories: before 21.1.10; before 22.0.11; before 23.0.3

References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-x75r-65hm-cw35
https://github.com/nextcloud/spreed/pull/17577
https://hackerone.com/reports/3636758

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