Input validation error in DOMPurify - CVE-2026-49458
Published: May 27, 2026
Vulnerability identifier: #VU132355
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-49458
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary script in the victim's browser.
The vulnerability exists due to improper input validation in the IN_PLACE sanitization logic when processing markup across realms. A remote attacker can supply specially crafted markup that bypasses realm-bound instanceof checks to execute arbitrary script in the victim's browser.
User interaction is required to process the crafted content.
Affected software
DOMPurify
How to mitigate CVE-2026-49458
Install security update from vendor's website.
DOMPurify - update to 3.4.6