Insufficient URL Validation in Claude Code by Anthropics
CVE-2026-24052

7.1HIGH

Key Information:

Vendor

Anthropics

Status
Claude-code
Vendor
CVE Published:
3 February 2026

What is CVE-2026-24052?

Claude Code, an agentic coding tool developed by Anthropics, prior to version 1.0.111, suffered from a security vulnerability due to inadequate URL validation in its trusted domain verification mechanism for WebFetch requests. The flawed implementation used the startsWith() function for domain validation, allowing attackers to potentially register deceptive domains (e.g., modelcontextprotocol.io.example.com) that could pass as trusted. This misconfiguration could result in the application making automatic requests to domains controlled by attackers without user consent, posing risks of unauthorized data access and exfiltration. The vulnerability has been addressed in the latest version.

Affected Version(s)

claude-code < 1.0.111

References

https://github.com/anthropics/claude-code/security/adviso...
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CVSS V4

Score:
7.1
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.