CVE-2026-45156Nextcloud: Authentication Bypass in ID4me handling via Missing JWT Signature Verification in User OIDC

Descripción

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.

Datos: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Se publican tal como los indican las fuentes, en inglés.

Productos y versiones afectados

Referencias y parches

• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-qqgv-fqwp-mjpp
• https://github.com/nextcloud/user_oidc/pull/1285
• https://hackerone.com/reports/3489490