CVE-2023-45151: Nextcloud Server

High severity, CVSS 8.8. EPSS: 0.5% chance of exploitation in the next 30 days.

Nextcloud server is an open source home cloud platform. Affected versions of Nextcloud stored OAuth2 tokens in plaintext which allows an attacker who has gained access to the server to potentially elevate their privilege. This issue has been addressed and users are recommended to upgrade their Nextcloud Server to version 25.0.8, 26.0.3 or 27.0.1. There are no known workarounds for this vulnerability.

Affected products

• Nextcloud Nextcloud Server: from 25.0.0, before 25.0.8 (fixed in 25.0.8); from 26.0.0, before 26.0.3 (fixed in 26.0.3); version 27.0.0 only

Published 2023-10-16. Last modified 2026-06-17.