SB2026060949 - Multiple vulnerabilities in HTML Sanitizer

Description

This security bulletin contains information about 2 vulnerabilities.

1) Cross-site scripting (CVE-ID: CVE-2026-47345)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to execute arbitrary script in a victim's browser.

The vulnerability exists due to cross-site scripting in HTML serialization of namespace attributes when processing sanitized HTML content. A remote attacker can supply specially crafted input to execute arbitrary script in a victim's browser.

The issue allows bypassing the cross-site scripting prevention mechanism.

2) Cross-site scripting (CVE-ID: CVE-2026-47344)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to execute arbitrary script code in a victim's browser.

The vulnerability exists due to cross-site scripting in the HTML sanitizer raw text handling when processing sanitized content with whitespace-variant closing tags while the ALLOW_INSECURE_RAW_TEXT option is enabled. A remote attacker can supply crafted input to execute arbitrary script code in a victim's browser.

Only configurations with the ALLOW_INSECURE_RAW_TEXT option enabled are vulnerable.

Remediation

Install update from vendor's website.

References

• https://github.com/TYPO3/html-sanitizer/security/advisories/GHSA-p5j5-4j3q-8mq8
• https://github.com/TYPO3/html-sanitizer/security/advisories/GHSA-jvf5-rxvv-3mcg