How severe is CVE-2025-66021?

CVE-2025-66021 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2025-66021 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-66021?

CVE-2025-66021 affects Owasp Java Html Sanitizer. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-66021?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-66021 have an EU (EUVD) identifier?

Yes. CVE-2025-66021 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-199654.

When was CVE-2025-66021 published?

CVE-2025-66021 was published on 2025-11-26 and last updated on 2026-06-17.

CVE-2025-66021

CVE-2025-66021 is a medium-severity vulnerability in Owasp Java Html Sanitizer with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v4: 8.6
EPSS exploit prediction: 0% (13th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-199654
Weakness: CWE-79
Affected product: Owasp Java Html Sanitizer
Published: 2025-11-26
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2025-66021?: CVE-2025-66021 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2025-66021 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-66021?: CVE-2025-66021 affects Owasp Java Html Sanitizer. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-66021?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-66021 have an EU (EUVD) identifier?: Yes. CVE-2025-66021 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-199654.
When was CVE-2025-66021 published?: CVE-2025-66021 was published on 2025-11-26 and last updated on 2026-06-17.

References

https://github.com/OWASP/java-html-sanitizer/security/advisories/GHSA-g9gq-3pfx-2gw2

Affected products (1)

cpe:2.3:a:owasp:java_html_sanitizer:20240325.1:*:*:*:*:*:*:*

More vulnerabilities in Owasp Java Html Sanitizer

CVE-2021-42575 — Critical (CVSS 9.8): The OWASP Java HTML Sanitizer before 20211018.1 does not properly enforce policies associated with the SELECT, STYLE,…

All CVEs affecting Owasp Java Html Sanitizer →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →