Coding Tool Vulnerability in Claude Code by Anthropic
CVE-2026-21852

5.3MEDIUM

Key Information:

Vendor

Anthropics

Status
Claude-code
Vendor
CVE Published:
21 January 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-21852?

A vulnerability in Claude Code allowed malicious repositories to exfiltrate sensitive user data, including Anthropic API keys, before users could confirm trust. Attackers could leverage a compromised repository to adjust the configuration to point to their own server. Once the repository was opened by the user, Claude Code would automatically attempt to connect and issue API requests without displaying the necessary trust prompt, risking exposure of user credentials. Users should ensure they are using version 2.0.65 or later to mitigate this risk.

Affected Version(s)

claude-code < 2.0.65

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-Archive
Created by M0broot

References

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

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

.