CVE-2022-46256 is a high-severity path traversal vulnerability (CWE-22) affecting GitHub Enterprise Server versions 3.3 through 3.7. This flaw allows an attacker with permission to create and build GitHub Pages sites on the affected instance to execute arbitrary code remotely. The vulnerability arises during the build process of GitHub Pages sites, where improper validation of file paths enables traversal outside the intended directory structure. By exploiting this, an attacker can manipulate file paths to access or overwrite files beyond the build context, ultimately leading to remote code execution on the server hosting the GitHub Enterprise instance. The vulnerability requires the attacker to have at least limited privileges (permission to create and build GitHub Pages sites), but does not require user interaction beyond that. The CVSS v3.1 base score is 8.8, reflecting its network attack vector, low complexity, required privileges, and high impact on confidentiality, integrity, and availability. The issue was responsibly disclosed through the GitHub Bug Bounty program and fixed in versions 3.3.17, 3.4.12, 3.5.9, 3.6.5, and 3.7.2. No known exploits in the wild have been reported to date. The vulnerability is particularly critical because GitHub Enterprise Server is widely used by organizations to host internal code repositories and manage software development workflows, meaning a successful exploit could compromise sensitive source code and disrupt development operations.

For European organizations, the impact of this vulnerability can be significant. Many enterprises, including government agencies, financial institutions, and large corporations across Europe, rely on GitHub Enterprise Server for secure code hosting and collaboration. Exploitation could lead to unauthorized access to proprietary source code, intellectual property theft, and potential insertion of malicious code into software projects. This could result in supply chain compromises affecting downstream customers and partners. Additionally, remote code execution on the server could allow attackers to disrupt development pipelines, cause denial of service, or pivot to other internal systems, escalating the breach impact. The requirement for build permissions limits the attack surface to insiders or compromised accounts, but insider threats or credential theft remain realistic risks. Given the critical role of software development in digital transformation initiatives in Europe, this vulnerability poses a threat to confidentiality, integrity, and availability of critical IT assets.

European organizations should prioritize upgrading GitHub Enterprise Server instances to the patched versions (3.3.17, 3.4.12, 3.5.9, 3.6.5, or 3.7.2) immediately to remediate this vulnerability. Beyond patching, organizations should audit and restrict permissions related to GitHub Pages site creation and builds, ensuring only trusted users have such capabilities. Implement strict access controls and monitor for anomalous build activities that could indicate exploitation attempts. Employ network segmentation to isolate GitHub Enterprise Servers from critical infrastructure to limit lateral movement in case of compromise. Regularly review and rotate credentials, and enforce multi-factor authentication to reduce risk from stolen or compromised accounts. Additionally, enable detailed logging and alerting on repository and build operations to detect suspicious behavior early. Conduct internal security training to raise awareness about the risks associated with build permissions and insider threats. Finally, consider integrating GitHub Enterprise Server with centralized security monitoring and incident response workflows to accelerate detection and remediation.