CVE-2025-42620
CVE-2025-42620 is a high-severity vulnerability with a CVSS 4.0 base score of 8.3. 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: High (CVSS 4.0 base score 8.3)
- EPSS exploit prediction: 0% (17th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2025-201710
- Weakness: CWE-79
- Published:
- Last modified:
Description
In affected versions, vulnerability-lookup handled user-controlled content in comments and bundles in an unsafe way, which could lead to stored Cross-Site Scripting (XSS). On the backend, the related_vulnerabilities field of bundles accepted arbitrary strings without format validation or proper sanitization. On the frontend, comment and bundle descriptions were converted from Markdown to HTML and then injected directly into the DOM using string templates and innerHTML. This combination allowed an attacker who could create or edit comments or bundles to store crafted HTML/JavaScript payloads which would later be rendered and executed in the browser of any user visiting the affected profile page (user.html). This issue affects Vulnerability-Lookup: before 2.18.0.
Frequently asked questions
- What is CVE-2025-42620?
- In affected versions, vulnerability-lookup handled user-controlled content in comments and bundles in an unsafe way, which could lead to stored Cross-Site Scripting (XSS). On the backend, the related_vulnerabilities field of bundles accepted arbitrary strings without format validation or proper sanitization. On the frontend, comment and bundle descriptions were converted from Markdown to HTML and then injected directly into the DOM using string templates and innerHTML. This combination allowed an attacker who could create or edit comments or bundles to store crafted HTML/JavaScript payloads which would later be rendered and executed in the browser of any user visiting the affected profile page (user.html). This issue affects Vulnerability-Lookup: before 2.18.0.
- How severe is CVE-2025-42620?
- CVE-2025-42620 has a CVSS 4.0 base score of 8.3, rated high severity.
- Is CVE-2025-42620 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2025-42620?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2025-42620 have an EU (EUVD) identifier?
- Yes. CVE-2025-42620 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-201710.
- When was CVE-2025-42620 published?
- CVE-2025-42620 was published on 2025-12-08 and last updated on 2026-06-17.
References
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…
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