CVE Catalog

CVE-2026-45156

HighCVSS 8.1
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.33%

25th percentile - higher than 25% of all known CVEs

Summary

Nextcloud (an open source content collaboration platform) 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 have a missing signature verification in User OIDC, allowing a malicious ID4me authority to impersonate any user.

Risk Assessment

An attacker can gain access to other users' accounts, including administrators, leading to data theft, content modification, or privilege escalation.

Recommendation

Update Nextcloud to version 3.1.0, 4.1.0, 5.1.0, 6.4.0, or 8.3.0 (depending on the major version).

Other vulnerabilities in Nextcloud

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS