What is CVE-2025-66021?

CVE-2025-66021 is a medium-severity vulnerability in Owasp Java-Html-Sanitizer, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2025-11-26.

How severe is CVE-2025-66021?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Owasp Java-Html-Sanitizer

CVE-2025-66021

OWASP Java HTML Sanitizer is a configureable HTML Sanitizer written in Java, allowing inclusion of HTML authored by third-parties in web applications while protecting against XSS. In version 20240325.1, OWASP java html sanitizer is vulnerable to XSS if HtmlPolicyBuilder allows noscript and style tags with allowTextIn inside the style tag. This could lead to XSS if the payload is crafted in such a way that it does not sanitise the CSS and allows tags which is not mentioned in HTML policy. At time of publication no known patch is available.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (16.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Owasp Java-html-sanitizer — versions = 20240325.1
Owasp Java_html_sanitizer — versions 20240325.1

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2025-66021?: CVE-2025-66021 is a medium-severity vulnerability in Owasp Java-Html-Sanitizer, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2025-11-26.
How severe is CVE-2025-66021?: Medium severity. CVSS v3 base score is 6.1 out of 10.