CVE-2025-59829 is a vulnerability identified in the anthropics claude-code agentic coding tool, specifically affecting versions prior to 1.0.120. The issue arises from improper handling of UNIX symbolic links (symlinks) in the context of permission deny rules. Claude Code's permission system is designed to restrict access to certain files based on user-defined deny rules. However, in affected versions, the software failed to correctly account for symlinks when enforcing these rules. This means that if a user explicitly denied Claude Code access to a particular file, but Claude Code had access to a symlink pointing to that file, the tool could bypass the deny rule and access the file indirectly through the symlink. This behavior constitutes a security flaw categorized under CWE-61, which concerns improper handling of symbolic links leading to potential unauthorized file access. The vulnerability is network exploitable (AV:N), requires low attack complexity (AC:L), and involves partial user interaction (UI:P). No privileges are required (PR:N), but partial attack traceability (AT:P) is noted. The impact on confidentiality and integrity is low, with no impact on availability. The issue was resolved in version 1.0.120, and users employing the standard auto-update mechanism would have received the fix automatically. Manual updaters are advised to upgrade promptly. No known exploits are currently reported in the wild, and the CVSS v4.0 base score is 2.3, indicating a low severity level. This vulnerability primarily affects UNIX-like operating systems where symlinks are commonly used and where claude-code is deployed. The flaw could allow unauthorized reading of files that users intended to restrict, potentially exposing sensitive data or violating privacy policies, depending on the files accessed.

For European organizations, the impact of CVE-2025-59829 is generally low but context-dependent. Organizations using anthropics claude-code in development or production environments on UNIX-based systems could face unauthorized access to files that were explicitly denied by users. This could lead to inadvertent exposure of sensitive source code, configuration files, or other proprietary data. While the vulnerability does not allow privilege escalation or denial of service, the unauthorized file access could undermine confidentiality and trust in internal security controls. Given the low CVSS score and no known active exploitation, the immediate risk is limited. However, organizations with strict data protection requirements under regulations such as GDPR should consider the potential for data leakage as a compliance concern. The vulnerability's reliance on symlink manipulation means that attackers would need some level of access to create or control symlinks in the environment, which may limit exploitation scenarios. Nonetheless, in multi-user or shared development environments common in European enterprises, this could be a vector for insider threats or lateral movement. Overall, the impact is low but should not be ignored in sensitive or regulated sectors.

To mitigate this vulnerability effectively, European organizations should: 1) Ensure all instances of anthropics claude-code are updated to version 1.0.120 or later, especially those updated manually. 2) Audit and restrict user permissions to prevent unauthorized creation or manipulation of symlinks in directories accessed by claude-code, reducing the risk of symlink-based bypass. 3) Implement file system monitoring to detect unusual symlink creation or access patterns that could indicate exploitation attempts. 4) Employ application whitelisting and sandboxing techniques to limit claude-code's file system access strictly to necessary directories. 5) Review and tighten deny rule configurations within claude-code to ensure they are comprehensive and tested against symlink scenarios. 6) Educate developers and system administrators about the risks of symlink attacks and encourage secure coding and deployment practices. 7) Integrate vulnerability scanning and patch management processes to promptly identify and remediate outdated claude-code versions. These steps go beyond generic advice by focusing on symlink-specific controls and operational practices tailored to the nature of this vulnerability.