Check Point Advisories

DOMPurify Security Bypass (CVE-2026-65903)

Vulnerability
Protection

Check Point Reference:	CPAI-2026-10263
Date Published:	23 Aug 2026
Severity:	High
Last Updated:	Sunday 23 August, 2026
Source:
Industry Reference:	CVE-2026-65903
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	DOMPurify prior to 3.4.0
Vulnerability Description	A security bypass vulnerability in cure53 DOMPurify allows attackers to craft input containing tags listed in FORBID_TAGS that are also added via ADD_TAGS function, causing them to be retained in sanitized output.

Protection Overview

This protection detects attempts to exploit this vulnerability.

In order for the protection to be activated, update your Security Gateway product to the latest IPS update. For information on how to update IPS, go to SBP-2006-05, click on Protection tab and select the version of your choice.

Security Gateway R81 / R80 / R77 / R75

In the IPS tab, click Protections and find the DOMPurify Security Bypass (CVE-2026-65903) protection using the Search tool and Edit the protection's settings.
Install policy on all Security Gateways.

This protection's log will contain the following information:

Attack Name: Application Intelligence.
Attack Information: DOMPurify Security Bypass (CVE-2026-65903)