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
nextcloud: nextcloud server
References4
- github.com/nextcloud/security-advisories/security/advisories/GH… PatchVendor Advisory
- hackerone.com/reports/3357808 Issue TrackingVendor Advisory
- github.com/nextcloud/viewer/commit/5044a27d61bc40c0f134298d36af… Patch
- github.com/nextcloud/viewer/pull/3023 Issue Tracking
Metrics
- CVSS 3.1
-
6.1
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 23 · as of 11 November 2026
- CWE
- CWE-80CWE-79
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.