CVE-2025-66032 is a command injection vulnerability classified under CWE-77 affecting anthropics' Claude Code, an agentic coding tool designed to assist in automated code generation and execution. The vulnerability exists in versions prior to 1.0.93 due to improper neutralization of special shell command elements, specifically related to the handling of the Internal Field Separator ($IFS) and short command-line interface (CLI) flags. This parsing error enables attackers to bypass the tool's read-only validation mechanisms, which are intended to prevent unauthorized code execution. By injecting specially crafted input containing shell metacharacters into a Claude Code context window, an attacker can execute arbitrary shell commands on the host system. Exploitation does not require prior authentication or privileges but does require the attacker to influence the content within the Claude Code context, implying some level of user interaction or social engineering. The vulnerability has been assigned a CVSS 4.0 base score of 8.7, reflecting its high impact on confidentiality, integrity, and availability, with network attack vector, low attack complexity, no privileges required, and user interaction needed. No public exploits have been reported yet, but the flaw poses a significant risk especially in environments where Claude Code is used for automated code execution or development workflows. The issue was addressed and patched in version 1.0.93, which corrects the command parsing logic to properly neutralize special shell elements and enforce read-only validation.

For European organizations, the impact of CVE-2025-66032 can be substantial, particularly for those relying on Claude Code for automated coding, DevOps pipelines, or software development automation. Successful exploitation could lead to arbitrary code execution on critical development or build servers, resulting in unauthorized access, data exfiltration, or disruption of software delivery processes. The compromise of development environments can also facilitate supply chain attacks, undermining software integrity and trust. Confidentiality of proprietary source code and intellectual property is at risk, as is the integrity of software artifacts produced. Availability may be affected if attackers deploy destructive payloads or ransomware. Given the high automation level in European tech sectors and the increasing adoption of AI-assisted coding tools, this vulnerability could be leveraged to target high-value assets. The requirement for user interaction and the ability to inject untrusted content somewhat limits the attack surface but does not eliminate risk, especially in environments with collaborative coding or where untrusted inputs are processed. The absence of known exploits currently provides a window for proactive mitigation.

European organizations should immediately upgrade all instances of Claude Code to version 1.0.93 or later to remediate the vulnerability. Beyond patching, organizations should enforce strict input validation and sanitization policies on all user-supplied content that may be processed by Claude Code, particularly in shared or collaborative environments. Implementing application-level sandboxing or containerization for Claude Code execution contexts can limit the impact of potential exploitation. Monitoring and logging of command execution within Claude Code should be enhanced to detect anomalous or unauthorized commands. Access controls should be tightened to restrict who can inject content into Claude Code context windows, minimizing exposure to untrusted inputs. Security awareness training should emphasize the risks of injecting untrusted content and the importance of verifying inputs. Additionally, organizations should review their software development lifecycle (SDLC) security practices to incorporate checks for vulnerabilities in AI-assisted coding tools. Network segmentation of development environments can further reduce lateral movement if exploitation occurs. Finally, maintain vigilance for any emerging exploit reports or indicators of compromise related to this CVE.