Review reviewCritical

CVE-2026-52842

lightpanda-io browser

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.

CVSS
9.3
EPSS
0.16%
5.73% percentile
CISA KEV
Not listed
Published
2026.07.16
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.16%
Technical severityCVSS 9.3

Vulnerability overview

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 product and versions

Product
lightpanda-io browser
Affected versions
>= < 0.3.1
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that lightpanda-io browser and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

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