Unrated severityNVD Advisory· Published Dec 5, 2025· Updated Dec 5, 2025
Nextcloud Server vulnerable to XSS in SVG images when opened outside of Nextcloud
CVE-2025-66512
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.
Affected products
2- nextcloud/security-advisoriesv5Range: >= 32.0.0beta1, < 32.0.3
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
4- github.com/nextcloud/security-advisories/security/advisories/GHSA-qcw2-p26m-9gc5mitrex_refsource_CONFIRM
- github.com/nextcloud/viewer/commit/5044a27d61bc40c0f134298d36af91f865335b63mitrex_refsource_MISC
- github.com/nextcloud/viewer/pull/3023mitrex_refsource_MISC
- hackerone.com/reports/3357808mitrex_refsource_MISC
News mentions
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