CVE-2026-49978

描述

If the HTML you give it contains a <template> element, and inside that template there's an element with a shadow DOM attached to it, DOMPurify quietly skips over the shadow contents. Whatever the attacker put in there - an image with an onerror handler, a link with a javascript: URL, even a full script - survives untouched. The moment the application uses that template the way templates are meant to be used (cloning it and inserting the result into the page), the malicious payload comes along and runs as if it had never been sanitized. From there an attacker gets everything XSS normally gets them: session cookies, stored tokens, the ability to act as the user, and the ability to leave persistent payloads behind for the next person who visits. [advisory.pdf](https://github.com/user-attachments/files/28275600/advisory.pdf) [poc.html](https://github.com/user-attachments/files/28275708/poc.html)

如何修補 CVE-2026-49978

要修補 CVE-2026-49978,請將受影響套件升級到下列已修補版本。

• —升級至 3.4.7 或更新版本

CVE-2026-49978 正在被利用嗎?

目前沒有被利用訊號。CVE-2026-49978 既不在 CISA KEV 也沒有最新的 EPSS 分數。

受影響套件(1)

• from 0, < 3.4.7

CVSS 分數

參考連結(2)

• PATCHgithub.com/cure53/DOMPurify
• WEBgithub.com/cure53/DOMPurify/security/advisories/GHSA-rp9w-3fw7-7cwq