CVE Feed

    Dashboard / CVE / CVE-2026-45156

    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 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.

    Published:Jun 1, 2026
    Last Modified:Jun 2, 2026
    EPS:Jun 1, 2026
    EPSS Score:0.00028
    CVSS Score:8.1

    Affected Products

    Vendor
    Nextcloud
    Product
    User Oidc

    Exploits

    https://github.com/cybertechajju/CVE-2026-45156-POC

    Common Weakness Enumeration

    CWE-287 Improper Authentication

    Related CVEs

    CVE-2026-45284 (CVSS 4.6) — Nextcloud is an open source content collaboration platform. From version 1.3.6 to before version 8.4.0, an imp…
    CVE-2026-45278 (CVSS 3.3) — Nextcloud is an open source content collaboration platform. From version 6.1.0 to before version 8.2.2, an att…
    CVE-2024-52512 (CVSS 3.3) — user_oidc app is an OpenID Connect user backend for Nextcloud. A malicious user could send a malformed login l…
    CVE-2024-37886 (CVSS 5.4) — user_oidc app is an OpenID Connect user backend for Nextcloud. An attacker could potentially trick the app int…
    CVE-2024-37312 (CVSS 6.3) — user_oidc app is an OpenID Connect user backend for Nextcloud. Missing access control on the ID4me endpoint al…
    CVE-2023-39954 (CVSS 3.8) — user_oidc provides the OIDC connect user backend for Nextcloud, an open-source cloud platform. Starting in ver…
    CVE-2023-39953 (CVSS 4.8) — user_oidc provides the OIDC connect user backend for Nextcloud, an open-source cloud platform. Starting in ver…
    CVE-2023-32074 (CVSS 8) — user_oidc app is an OpenID Connect user backend for Nextcloud. Authentication can be broken/bypassed in user_o…
    CVE-2023-28848 (CVSS 4.8) — user_oidc is the OIDC connect user backend for Nextcloud, an open source collaboration platform. A vulnerabili…

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High