What is CVE-2025-66458?

CVE-2025-66458 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-2025-66458?

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

XSS in Lookyloo

CVE-2025-66458

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, there are multiple XSS due to unsafe use of f-strings in Markup. The issue requires a malicious 3rd party server responding with a JSON document containing JS code in a script element. This vulnerability is fixed in 1.35.3.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (6.0th 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

Lookyloo — versions < 1.35.3

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

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

Frequently asked questions

What is CVE-2025-66458?: CVE-2025-66458 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-2025-66458?: Medium severity. CVSS v3 base score is 6.1 out of 10.