CVE-2025-11148 is a critical command injection vulnerability affecting all versions of the 'check-branches' package, a command-line tool used locally or in continuous integration (CI) environments to verify the absence of conflicts in git branches. The vulnerability arises because the tool trusts branch names as plain text inputs and constructs git commands by concatenating these branch names directly into shell commands without proper sanitization or escaping. Since branch names can be user-controlled—either through remote pull requests or by users with repository access—an attacker can craft malicious branch names containing shell command payloads. When 'check-branches' processes these branch names, it inadvertently executes arbitrary commands with the privileges of the user running the tool. This leads to a classic command injection scenario (CWE-78) with a CVSS 3.1 base score of 9.8, indicating critical severity. The attack vector is network-based (AV:N), requires no privileges (PR:N), no user interaction (UI:N), and impacts confidentiality, integrity, and availability (C:H/I:H/A:H). Although no known exploits are reported in the wild yet, the vulnerability's nature and ease of exploitation make it a significant risk, especially in automated CI pipelines where branch names are processed automatically. The lack of available patches at the time of disclosure further increases the urgency for mitigation.

For European organizations, the impact of this vulnerability can be severe. Many enterprises rely on CI/CD pipelines that automate code integration and testing, often using tools like 'check-branches' to ensure branch consistency. Exploitation could allow attackers to execute arbitrary commands on build servers or developer machines, potentially leading to unauthorized access, data exfiltration, or disruption of development workflows. This could compromise sensitive intellectual property, customer data, or internal infrastructure. Given the critical severity and the fact that exploitation does not require authentication or user interaction, attackers could leverage malicious pull requests or compromised accounts to inject commands. This risk is heightened in organizations with collaborative development models, open-source contributions, or third-party integrations. Additionally, disruption of CI pipelines can delay software releases and impact business continuity. The vulnerability also poses a risk to supply chain security, as compromised build environments can propagate malicious code downstream.

To mitigate this vulnerability, European organizations should immediately audit their use of the 'check-branches' tool in local and CI environments. Specific recommendations include: 1) Avoid using 'check-branches' until a patched version is released; 2) If usage is unavoidable, implement strict branch naming policies that disallow special characters or shell metacharacters to prevent injection payloads; 3) Sanitize and validate branch names rigorously before processing; 4) Run CI jobs with the least privilege principle, restricting permissions of the user executing 'check-branches' to minimize potential damage; 5) Employ containerization or sandboxing for CI jobs to isolate potential command execution; 6) Monitor CI logs and system activity for suspicious command executions or anomalies; 7) Consider alternative tools or custom scripts that safely handle branch names; 8) Educate developers and repository maintainers about the risks of accepting untrusted branch names; 9) Implement network segmentation and access controls to limit exposure of build infrastructure; 10) Stay updated on vendor advisories and apply patches promptly once available.