CVE-2026-49978

A flaw was found in DOMPurify, a tool designed to sanitize HTML, MathML, and SVG to prevent cross-site scripting (XSS) attacks. When performing in-place sanitization, DOMPurify could fail to properly process content within shadow DOM elements attached to a <template>.content. This oversight allows an attacker to embed malicious code, such as JavaScript, which could then execute when the sanitized template is used by an application, potentially leading to unauthorized actions or information disclosure.

This vulnerability in DOMPurify is rated as Important as it allows for cross-site scripting (XSS) attacks. When DOMPurify performs in-place sanitization, it may fail to properly process shadow DOM content within <template>.content, enabling an attacker to embed and execute malicious JavaScript. This could lead to unauthorized actions or information disclosure in Red Hat products that utilize DOMPurify for sanitizing untrusted HTML, MathML, or SVG.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.