CVE-2026-45690
Nextcloud: Two-Factor Authentication Bypass via Pending Session Token Replay
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
How to fix CVE-2026-45690
To remediate CVE-2026-45690, upgrade the affected package to a fixed version below.
- —upgrade to 32.0.9 or later
Is CVE-2026-45690 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 32.0.0, < 32.0.9, >= 33.0.0, < 33.0.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.9 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N |