🛡️ CVE-2025-66512 — nextcloud-server

🟡 CVSS 5.4 — Medium ✅ No Known Exploit CWE-80 NVD
5.4
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Nextcloud Server is a self hosted personal cloud system. In Nextcloud Server and Server Enterprise prior to 31.0.12 and 32.0.3, a missing sanitization allowed malicious users to circumvent the content security policy when a malicious user manages to trick a user it viewing an uploaded SVG outside of the Nextcloud Servers web page.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity low, availability low.

Affected software

CVE-2025-66512 is recorded against 1 package.

  • nextcloud-server (from 32.0.0 up to 32.0.3)

Timeline and source

Published on 5 December 2025 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com
github.com
github.com
hackerone.com

Details

Severity MEDIUM
CVSS Score 5.4
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
CWE CWE-80
Public Exploit ✅ No
Source NVD
Published 2025-12-05
Updated 2026-08-11
Modified 2026-06-17

Affected Packages

Software From version Fixed in
nextcloud-server 32.0.0 32.0.3

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