CVE-2026-45690

nextcloud: Improper Authentication (CVE-2026-45690)

mediumEPSS 0.3%

Description

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, an authentication bypass vulnerability allowed attackers with knowledge of a user's password to circumvent two-factor authentication (2FA) protections. When a user initiated login with valid credentials on a 2FA-enabled account, the system created a temporary session token before enforcing the second factor challenge. This token could be extracted and replayed via HTTP Basic Authentication to gain unauthorized access to authenticated endpoints. It is recommended that the Nextcloud Server is upgraded to 33.0.3 or 32.0.9. It is recommended that the Nextcloud Enterprise Server is upgraded to 33.0.3, 32.0.9, 31.0.14.5, 30.0.17.9 or 29.0.16.16

Metrics

Severity
medium
no public PoC known
5.9
Source: nvd-v3
21.4 %
Elevated — this CVE ranks above at least 10% of all CVEs scored today.
0.3 %
Low — model estimates < 1% exploitation likelihood.
Published
2026-06-01 19:16 UTC
CWE-287

Weakness classes (CWE)

  • CWE-287Class

    Improper Authentication

    When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

    cwe.mitre.org →

Affected products

Products and version ranges extracted from the vendor/CERT advisory. A range like „<4.14.6“ implies the update recommendation „upgrade to 4.14.6 or later“.

  • bitnami

    nextcloud32.0.0

  • bitnami

    nextcloud33.0.0

References & sources

IDCVE-2026-45690