CVE-2023-38500: TYPO3 HTML Sanitizer is an HTML sanitizer, written in PHP, aiming to provide cross-site-scripting-safe markup based on explicitly allowed tags, attrib...

Description

TYPO3 HTML Sanitizer is an HTML sanitizer, written in PHP, aiming to provide cross-site-scripting-safe markup based on explicitly allowed tags, attributes and values. Starting in version 1.0.0 and prior to versions 1.5.1 and 2.1.2, due to an encoding issue in the serialization layer, malicious markup nested in a `noscript` element was not encoded correctly. `noscript` is disabled in the default configuration, but might have been enabled in custom scenarios. This allows bypassing the cross-site scripting mechanism of TYPO3 HTML Sanitizer. Versions 1.5.1 and 2.1.2 fix the problem.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.43%

34.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Typo3	Html Sanitizer	>= 1.0.0, < 1.5.1
Typo3	Html Sanitizer	>= 2.0.0, < 2.1.2

References

Timeline

Published: Jul 25, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-38500?

TYPO3 HTML Sanitizer is an HTML sanitizer, written in PHP, aiming to provide cross-site-scripting-safe markup based on explicitly allowed tags, attributes and values. Starting in version 1.0.0 and prior to versions 1.5.1 and 2.1.2, due to an encoding issue in the serialization layer, malicious markup nested in a `noscript` element was not encoded correctly. `noscript` is disabled in the default configuration, but might have been enabled in custom scenarios. This allows bypassing the cross-site scripting mechanism of TYPO3 HTML Sanitizer. Versions 1.5.1 and 2.1.2 fix the problem.

How severe is CVE-2023-38500?

CVE-2023-38500 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.43% probability of exploitation in the next 30 days.

How do I fix CVE-2023-38500?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.