The vulnerability identified as CVE-2026-24842 affects the node-tar package, a widely used TAR archive utility for Node.js environments. The root cause is a discrepancy between the path resolution semantics used in the security check for hardlink entries and those used during the actual hardlink creation process. Specifically, the security check attempts to prevent path traversal attacks by validating the target paths of hardlinks, but due to inconsistent path normalization or resolution methods, an attacker can craft a malicious TAR archive that bypasses these checks. This allows the creation of hardlinks pointing to arbitrary files outside the intended extraction directory. Such behavior violates the principle of restricting file operations within a safe directory boundary, enabling attackers to potentially overwrite or link to sensitive system or application files. The vulnerability affects all node-tar versions prior to 7.5.7, where the issue was addressed by harmonizing the path resolution logic and strengthening the validation process. The CVSS v3.1 score of 8.2 (high) reflects the network attack vector, low attack complexity, no privileges required, but requiring user interaction to extract the malicious archive. The impact primarily concerns confidentiality, as attackers can access or link to sensitive files, with limited integrity impact and no direct availability impact. No known exploits have been reported in the wild yet, but the vulnerability is critical enough to warrant immediate attention in environments processing untrusted TAR archives with node-tar.

For European organizations, this vulnerability poses a significant risk especially for those developing or deploying Node.js applications that handle TAR archive extraction using node-tar versions prior to 7.5.7. Exploitation could lead to unauthorized access to sensitive files, such as configuration files, credentials, or source code, potentially resulting in data breaches or further system compromise. Organizations in sectors with strict data protection regulations, such as finance, healthcare, and government, could face compliance violations and reputational damage if exploited. The ability to create hardlinks outside the extraction directory may also facilitate privilege escalation or lateral movement within compromised environments. Since node-tar is commonly used in development and deployment pipelines, CI/CD systems, and container build processes, the vulnerability could affect software supply chains, increasing the risk of widespread impact. The requirement for user interaction (extracting the archive) somewhat limits automated exploitation but does not eliminate risk, especially in environments where TAR files are routinely processed from external sources. Overall, the vulnerability threatens confidentiality and integrity of critical files in European organizations relying on vulnerable node-tar versions.

European organizations should immediately upgrade all instances of node-tar to version 7.5.7 or later, where the vulnerability is fixed. In addition, implement strict validation and sanitization of TAR archives before extraction, especially those originating from untrusted or external sources. Employ sandboxed or isolated environments for archive extraction to limit the impact of potential exploitation. Integrate security scanning tools in CI/CD pipelines to detect usage of vulnerable node-tar versions and prevent deployment of affected software. Monitor logs and file system changes for suspicious hardlink creation or unexpected file modifications. Educate developers and DevOps teams about the risks of processing untrusted archives and enforce policies restricting such operations. Where upgrading is not immediately possible, consider using alternative archive extraction libraries with robust path traversal protections. Finally, maintain an inventory of applications and services using node-tar to ensure comprehensive remediation.