Description
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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| nextcloud | security-advisories | >= 0.3.0, < 3.1.0, >= 5.0.0, < 5.1.0, >= 6.0.0, < 6.4.0 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
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cybertechajju/CVE-2026-45156-POC ★ 2 · Jun 23, 2026
This repository contains the Proof of Concept (PoC) exploit script for CVE-2026-45156
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- WID-SEC-2026-1471 Nextcloud: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 1, 2026