CVE-2025-66512
Title: Nextcloud Server Missing Sanitization Leads to Content Security Policy Bypass
XSS
Proof Of Concept
No public PoC currently indexed for CVE-2025-66512.
CWE Category
CWE-79
Published Date
Dec 05, 2025
Modified Date
Dec 09, 2025
Exploit Status
Not Found
Score
5.4
CVSS v3.1
Exploit Probability (EPSS)
0.28%
Vulnerability Summary
CVE-2025-66512: 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.
Impacted Vendors
Reference Links
CVSS v3.1
Source Entity
[email protected]
Severity
MEDIUM
5.4
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
CVSS v3.1
Source Entity
[email protected]
Severity
MEDIUM
6.1
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
CHANGED
RAW VECTOR
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Associated Attack Patterns (CAPEC)
Total: PatternsNo specific attack patterns mapped.
Likelihood
Severity
Page /
CVE-2025-66512 Exploits & PoCs (Proof Of Concept)
No public PoCs found in our database for this CVE.
MODIFIED
Vulnerability data or affected products updated.
MODIFIED
Vulnerability data updated via NVD.
PUBLISHED
Vulnerability first announced in NVD.
Attack Vector Matrix
Access Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
CVSS Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
Affected Stack
No specific products linked.