CVE-2026-52842: Lightpanda-Io Browser

Critical severity, CVSS 9.3. EPSS: 0.2% chance of exploitation in the next 30 days.

Lightpanda is a headless browser designed for AI and automation. Prior to 0.3.1, Lightpanda searched for @ across the entire URL string instead of only the authority component when computing a page origin, so a URL such as `http://attacker.com/@victim.com/` was fetched from attacker.com but treated as `http://victim.com`, allowing a complete Same-Origin Policy bypass. This issue is fixed in version 0.3.1.

Affected products

• Lightpanda-Io Browser: before 0.3.1 (fixed in 0.3.1)

Published 2026-07-15. Last modified 2026-07-15.