XSS in Lookyloo

CVE-2025-66459

Lookyloo is a web interface that allows users to capture a website page and then display a tree of domains that call each other. Prior to 1.35.3, a XSS vulnerability can be triggered when a user submits a list of URLs to capture, one of them contains a HTML element, and the capture fails. Then, the error field is populated with an error message that contains the bad URL they tried to capture, triggering the XSS. This vulnerability is fixed in 1.35.3.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.003 (18.9th 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

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-66459?
CVE-2025-66459 is a medium-severity vulnerability in Lookyloo, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2025-12-02.
How severe is CVE-2025-66459?
Medium severity. CVSS v3 base score is 6.1 out of 10.