Bug 2520367 - CVE-2026-65912 nextcloud: DOMPurify: URI validation bypass leads to cross-site scripting [fedora-all]
Summary: CVE-2026-65912 nextcloud: DOMPurify: URI validation bypass leads to cross-sit...
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Fedora
Classification: Fedora
Component: nextcloud
Version: rawhide
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: ---
Assignee: Andrew Bauer
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["c1e6b029-b965-4e40-bc75-0...
Depends On:
Blocks: CVE-2026-65912
TreeView+ depends on / blocked
 
Reported: 2026-08-20 14:53 UTC by Ganesh
Modified: 2026-08-20 15:15 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2026-08-20 15:15:43 UTC
Type: ---
Embargoed:


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Description Ganesh 2026-08-20 14:53:39 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

DOMPurify before 3.3.2 contains a URI validation bypass vulnerability when ADD_ATTR is provided as a predicate function via EXTRA_ELEMENT_HANDLING.attributeCheck. Attackers can supply a predicate that accepts specific attribute and tag combinations to bypass URI-safe validation, allowing unsafe protocols like javascript: to survive sanitization and execute as DOM-based XSS when the link is activated.

Comment 1 Andrew Bauer 2026-08-20 15:15:43 UTC
This bug is not valid. As of this writing, the current Nextcloud 34.0.3 release contain DOMPurify 3.4.13 which does not contain this CVE.

See:
https://github.com/nextcloud/server/blob/v34.0.3/package-lock.json#L6512


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