Is CVE-2026-52842 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-52842?

CVE-2026-52842 has a CVSS v3 severity of CRITICAL (9.3).

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CVE-2026-52842

Description

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.