CVE-2026-45690

What it is

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

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data tampering.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-01 19:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-22 08:10 UTC Last updatedMost recent change to the record

Details

Published

2026-06-01 19:16 UTC

Last modified

2026-07-22 08:10 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-287 · Improper authentication

Record status

Analyzed

Affected

• Nextcloud Server < 32.0.9
• Nextcloud Server < 33.0.3
• Nextcloud Server < 29.0.16.16
• Nextcloud Server < 30.0.17.9
• Nextcloud Server < 31.0.14.5

Attack profile CVSS 3.1 · 5.9

Attack vector

Network

Complexity

High

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

High

Availability

None