GHSA-p5j5-4j3q-8mq8

TYPO3 HTML Sanitizer allows Cross-site Scripting

Source: GitHub Advisory Database (reviewed) Moderate CVE-2026-47345

Packages

Ecosystem	Package	Affected	Fixed in
Packagist	typo3/html-sanitizer	< 2.3.2	2.3.2

Details

As written in the advisory (Markdown source, shown as plain text).

Namespace attributes are not encoded correctly during HTML serialization. This allows bypassing the cross-site scripting prevention mechanism of `typo3/html-sanitizer` before version 2.3.2. Credits to Doyensec in collaboration with Claude and Anthropic Research for reporting this vulnerability.

References

External links from the advisory. They lead to third-party sites.

https://github.com/TYPO3/html-sanitizer/security/advisories/GHSA-p5j5-4j3q-8mq8 web
https://nvd.nist.gov/vuln/detail/CVE-2026-47345 advisory
https://github.com/TYPO3/html-sanitizer/commit/8b5d0be44ded457ca993ec9ca93d859941c63764 web
https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/html-sanitizer/CVE-2026-47345.yaml web
https://github.com/TYPO3/html-sanitizer package
https://typo3.org/security/advisory/typo3-core-sa-2026-006 web