by Kastro
Paper/Archive/CVE-2026-52842

CVE-2026-52842

lightpanda-io browser — Lightpanda:URL parser misidentifies page origin for URLs containing @ in the path - Same-Origin Policy bypass

EPSS 0.2%CVSS 9.3
critical.is priorityof 100
31
CVSS 9.3 (CNA)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 15.9.159 × 203.2No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
browser< 0.3.1–CNA

Scores by source

GitHub_M (CNA)9.3CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refgithub.com/lightpanda-io/browser/security/advisories/GHSA-mq6p-m9cc-q432refgithub.com/lightpanda-io/browser/pull/1998refgithub.com/lightpanda-io/browser/commit/0588cc374d4af9687cf6f45a7d52f7af04bbacfbrefgithub.com/lightpanda-io/browser/releases/tag/0.3.1