Nextcloud Server vulnerable to XSS in SVG images when opened outside of Nextcloud
Priority LOW 27CWE-80Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-80.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00301 22nd percentileScored 2026-11-07
Fix Fixed security-advisories (nextcloud): 32.0.3, 31.0.12
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| nextcloud | security-advisories | 32.0.0beta1 to before 32.0.3; before 31.0.12 | 32.0.3, 31.0.12 | Patch available | CNA |
- security-advisories Vendornextcloud Affected 32.0.0beta1 to before 32.0.3; before 31.0.12 Fixed in 32.0.3, 31.0.12 Patch available CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* | 31.0.0 to before 31.0.12 | Vulnerable | nextcloud |
| cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* | 31.0.0 to before 31.0.12 | Vulnerable | nextcloud |
| cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* | 32.0.0 to before 32.0.3 | Vulnerable | nextcloud |
| cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* | 32.0.0 to before 32.0.3 | Vulnerable | nextcloud |
- cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* Versions 31.0.0 to before 31.0.12 Vulnerable ·nextcloud
- cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* Versions 31.0.0 to before 31.0.12 Vulnerable ·nextcloud
- cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* Versions 32.0.0 to before 32.0.3 Vulnerable ·nextcloud
- cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* Versions 32.0.0 to before 32.0.3 Vulnerable ·nextcloud
Remediation
- Fix · CNA security-advisories (nextcloud) Fixed in 32.0.3, 31.0.12
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2025-66512
References
More Nextcloud Server vulnerabilities
- TI-2023-20855 Users can delete external storage mount points CVSS 3.1HIGH 7.7
- TI-2023-11091 Nextcloud download permissions can be changed by resharer CVSS 3.1HIGH 7.5
- TI-2023-10624 Nextcloud Server vulnerable to SSRF via filter bypass due to lax checking on IPs CVSS 3.1MEDIUM 5.3
- TI-2025-37238 Cross-site scripting in Nextcloud CVSS 3.1MEDIUM 6.4
- TI-2023-11086 nextcloud vulnerable to Uncontrolled Resource Consumption CVSS 3.1MEDIUM 6.5
- TI-2022-18738 Exception logging in Sharepoint app reveals clear-text connection details CVSS 3.1MEDIUM 6.5
Sources
- CVE-2025-66512 · CVE Program
- CVE-2025-66512 · NVD
- FIRST EPSS
- CVE-2025-66512 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences