CVE-2026-52842 Lightpanda:URL parser misidentifies page origin for URLs containing @ in the path - Same-Origin Policy bypass
Lightpanda's URL parser incorrectly handles '@' in paths, allowing attackers to bypass Same-Origin Policy restrictions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-52842?
CVE-2026-52842 is a critical vulnerability in lightpanda-io browser, published on 15 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
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.
Weakness: CWE-346
Which versions are affected by CVE-2026-52842?
How do I fix CVE-2026-52842?
No fix has been published for CVE-2026-52842 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-52842 being exploited?
There is no known exploitation of CVE-2026-52842 in the wild and no public exploit code.
Sources
Also known as GHSA-mq6p-m9cc-q432.