Vulnerability · Published Jul 15, 2026 · Assigned by GitHub_M

CVE-2026-52842Lightpanda:URL parser misidentifies page origin for URLs containing @ in the path - Same-Origin Policy bypass

Critical 9.3

In plain English

A critical-severity security flaw in browser from lightpanda-io. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities).

Severity (CVSS 3.1)9.3Critical

Exploit odds (30 days)0.2%top 84.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
lightpanda-io	browser	< 0.3.1

Weakness: CWE-346 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

References

https://github.com/lightpanda-io/browser/security/advisories/GHSA-mq6p-m9cc-q432 x_refsource_CONFIRM
https://github.com/lightpanda-io/browser/pull/1998 x_refsource_MISC
https://github.com/lightpanda-io/browser/commit/0588cc374d4af9687cf6f45a7d52f7af04bbacfb x_refsource_MISC
https://github.com/lightpanda-io/browser/releases/tag/0.3.1 x_refsource_MISC