High

Claude Code has a Domain Validation Bypass which Allows Automatic Requests to Attacker-Controlled Domains

  • Disclosed: 03.02.2026
  • Updated: 11.10.2026 10:22

Claude Code contained insufficient URL validation in its trusted domain verification mechanism for WebFetch requests. The application used a startsWith() function to validate trusted domains (e.g., docs.python.org, modelcontextprotocol.io), this could have enabled attackers to register domains like modelcontextprotocol.io.example.com that would pass validation. This could enable automatic requests to attacker-controlled domains without user consent, potentially leading to data exfiltration.

Users on standard Claude Code auto-update have received this fix already. Users performing manual updates are advised to update to the latest version.

Thank you to hackerone.com/47sid-praetorian for reporting this issue!

Affected software

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PlatformPackageVulnerable versionsFixed in
npm package @anthropic-ai/claude-code < 1.0.111 1.0.111

References

CVSS score -
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness (CWE)
CWE-601
Platform
npm
Package
@anthropic-ai/claude-code
Disclosed
03.02.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-vhw5-3g5m-8ggf - CC BY 4.0

Vulnerability history: @anthropic-ai/claude-code

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (29) in the archive
Total entries
29
First → latest
06.2025 10.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • High 23
  • Medium 4
  • Low 2

Disclosures per year

  1. 2025: 13
  2. 2026: 16
Severity:
  1. Claude Code has a Domain Validation Bypass which Allows Automatic Requests to Attacker-Controlled Domains this entry
    High CVE-2026-24052 < 1.0.111 1.0.111
Show more (3) Showing 20 of 23

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