Medium severity5.4NVD Advisory· Published Dec 5, 2025· Updated Jun 17, 2026

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.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

Nextcloud/Server2 versions
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*+ 1 more
- cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*range: >=31.0.0,<31.0.12
- cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*range: >=31.0.0,<31.0.12
Nextcloud/viewerllm-create
Nextcloud/Nextcloud Enterprise Serverllm-fuzzy
Range: <31.0.12 and <32.0.3
Nextcloud/security-advisoriescpe-rescue
Range: >= 32.0.0beta1, < 32.0.3

Patches

Vulnerability mechanics

References

github.com/nextcloud/security-advisories/security/advisories/GHSA-qcw2-p26m-9gc5nvdPatchVendor Advisory
github.com/nextcloud/viewer/commit/5044a27d61bc40c0f134298d36af91f865335b63nvdPatch
hackerone.com/reports/3357808nvdIssue TrackingVendor Advisory
github.com/nextcloud/viewer/pull/3023nvdIssue Tracking

News mentions

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