CVE intelligence and bounded remediation

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

Medium CVSS 6.1

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.

Severity
Medium
CVSS
6.1 (3.1)
Published
2025-12-02
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-79

Affected products

  • lookyloo / lookyloo

Matched remediation archetype

Cross-site scripting and unsafe browser output

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.