# CVE-2026-47344: TYPO3 html-sanitizer XSS bypass via whitespace-variant closing tags

Source: https://junglewise.ai/threats/cve-2026-47344-typo3-html-sanitizer-xss-bypass-via-whitespace-variant-closing  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-08. Updated: 2026-06-12  
License: CC BY 4.0 with a link back

CVE-2026-47344 · Severity: medium · CVSS 4 · Published 2026-06-08

The TYPO3 HTML Sanitizer, a tool used to clean user-provided content and prevent malicious scripts from running in web browsers, contains a flaw when a specific insecure text mode is enabled. An attacker could bypass the security filters by using specially formatted HTML tags that the sanitizer ignores but browsers still execute. This could lead to cross-site scripting (XSS) attacks, potentially allowing unauthorized actions in a user's session.

Technologies: [typo3/html-sanitizer (Packagist)](https://junglewise.ai/threats/technologies/typo3-html-sanitizer). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist), [Typo3](https://junglewise.ai/threats/vendors/typo3).

## Quick answers

**Is CVE-2026-47344 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-47344 being exploited in the wild.

**How severe is CVE-2026-47344?** Medium severity, with a CVSS score of 4, published 8 June 2026.

**Which products and versions are affected?** typo3/html-sanitizer (Packagist) < 2.3.2, ECOSYSTEM:introduced=0,fixed=2.3.2; Typo3 Html-Sanitizer < 2.3.2.

**Is there a fix for CVE-2026-47344?** Yes. typo3/html-sanitizer (Packagist): upgrade to 2.3.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-47344 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-47344?** Check whether you run typo3/html-sanitizer (Packagist) or Typo3 Html-Sanitizer at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- typo3/html-sanitizer (Packagist): upgrade to 2.3.2 or later

  ```sh
  composer require typo3/html-sanitizer:^2.3.2
  ```


## Technical details

A cross-site scripting (XSS) vulnerability exists in the TYPO3 HTML Sanitizer when the ALLOW_INSECURE_RAW_TEXT configuration is enabled. The root cause is a discrepancy between how the sanitizer and web browsers parse closing tags containing whitespace characters (such as tabs). While the sanitizer fails to recognize these as valid end tags, browsers treat them as legitimate, allowing an attacker to break out of raw text elements (like <style> or <script>) and inject malicious markup. This bypasses the library's primary XSS prevention mechanism. The issue is fixed in version 2.3.2.

## Affected products

- TYPO3 html-sanitizer < 2.3.2

## Identifiers

- CVE-2026-47344
- GHSA-jvf5-rxvv-3mcg

## Timeline

- 2026-06-08: disclosed
- 2026-06-12: advisory

## References

- [https://api.github.com/users/ohader](https://api.github.com/users/ohader)
- [https://github.com/ohader](https://github.com/ohader)
- [https://api.github.com/users/ohader/gists%7B/gist_id%7D](https://api.github.com/users/ohader/gists%7B/gist_id%7D)
- [https://api.github.com/users/ohader/repos](https://api.github.com/users/ohader/repos)
- [https://avatars.githubusercontent.com/u/402145?v=4](https://avatars.githubusercontent.com/u/402145?v=4)
- [https://api.github.com/users/ohader/events%7B/privacy%7D](https://api.github.com/users/ohader/events%7B/privacy%7D)

## Related threats

- [TYPO3 html-sanitizer XSS bypass via incorrect namespace encoding](https://junglewise.ai/threats/cve-2026-47345-typo3-html-sanitizer-xss-bypass-via-incorrect-namespace-encoding)
- [Bypassing Cross-Site Scripting Protection in TYPO3 HTML Sanitizer](https://junglewise.ai/threats/cve-2023-47125-bypassing-cross-site-scripting-protection-in-typo3-html-sanitizer)
- [By-passing Cross-Site Scripting Protection in HTML Sanitizer](https://junglewise.ai/threats/cve-2023-38500-by-passing-cross-site-scripting-protection-in-html-sanitizer)
- [TYPO3 HTML Sanitizer vulnerable to Cross-Site Scripting](https://junglewise.ai/threats/cve-2022-23499-typo3-html-sanitizer-vulnerable-to-cross-site-scripting)
- [TYPO3 HTML Sanitizer Bypasses Cross-Site Scripting Protection](https://junglewise.ai/threats/cve-2022-36020-typo3-html-sanitizer-bypasses-cross-site-scripting-protection)