CVE-2025-66512
mediumpriority · track · 24EPSS 0.003 · 20 %ileDEEURUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (15)
Products and version ranges known to be affected.
- Nextcloud Nextcloud Enterprise Serverall versionscert_bundDEcpe:/a:nextcloud:nextcloud:enterprise_server
advisories (1)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2025-2752Nextcloud: Mehrere SchwachstellenDeutsch2025-12-04csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Nextcloud ausnutzen, um Dateien zu manipulieren, um Informationen offenzulegen, um einen Cross-Site Scripting Angriff durchzuführen, um Sicherheitsvorkehrungen zu umgehen, und um falsche Informationen darzustellen.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (14)
External citations — patches, advisories, analysis.
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-qcw2-p26m-9gc5cnnvd
- https://github.com/nextcloud/viewer/commit/5044a27d61bc40c0f134298d36af91f865335b63cnnvd
- https://github.com/nextcloud/viewer/pull/3023cnnvd
- https://hackerone.com/reports/3357808cnnvd
- https://nextcloud.com/install/#instructions-serverPatchcnnvd
- https://vigilance.fr/vulnerability/Nextcloud-Server-Cross-Site-Scripting-via-SVG-Images-49001cnnvd
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-qcw2-p26m-9gc5enisa_euvd
- https://github.com/nextcloud/viewer/commit/5044a27d61bc40c0f134298d36af91f865335b63enisa_euvd
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