CVE-2026-45156: Nextcloud is an open source content collaboration platform. From versions 0.3.0 to before 3.1.0, 5.0.0 to before 5.1.0, and 6.0.0 to before 6.4.0, a missing…

PriorityP345high8.1CVSS 3.1

AVNACLPRNUIRSUCHIHAN

EPSS

0.33%

24.6th percentile

Nextcloud is an open source content collaboration platform. From versions 0.3.0 to before 3.1.0, 5.0.0 to before 5.1.0, and 6.0.0 to before 6.4.0, a missing signature verification in User OIDC allowed a malicious ID4me authority to identify as any user. This issue has been patched in versions 3.1.0, 4.1.0, 5.1.0, 6.4.0 and 8.3.0.

Affected

3 ranges

Vendor	Product	Version range	Fixed in
nextcloud	security-advisories	—	—
nextcloud	security-advisories	—	—
nextcloud	security-advisories	—	—

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