Cross-site scripting in DOMPurify - CVE-2026-75838
Published: August 4, 2026 / Updated: September 14, 2026
Vulnerability identifier: #VU140846
CSH Severity: Low
CVSS v4: 2.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-75838
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary JavaScript in the application's origin.
The vulnerability exists due to cross-site scripting in _sanitizeElements() when sanitizing attacker-supplied HTML with IN_PLACE enabled and an element-removal hook detaches the current node. A remote user can supply crafted HTML containing a descendant resource element with an event handler to execute arbitrary JavaScript in the application's origin.
User interaction is required to render the sanitized content, and exploitation requires the non-default IN_PLACE configuration together with a hook that removes a containing element.
Affected software
DOMPurify
Fedora
nextcloud
Fedora
nextcloud
How to mitigate CVE-2026-75838
Install security update from vendor's website.
DOMPurify - update to 3.4.13
nextcloud - addressed in versions 34.0.4-1.el10_2, 34.0.4-1.el10_4, 34.0.4-1.fc43, 34.0.4-1.fc44, 34.0.4-1.fc45
nextcloud - addressed in versions 34.0.4-1.el10_2, 34.0.4-1.el10_4, 34.0.4-1.fc43, 34.0.4-1.fc44, 34.0.4-1.fc45