CVE-2025-6981 is an authorization vulnerability classified under CWE-863 (Incorrect Authorization) affecting GitHub Enterprise Server versions prior to 3.18, specifically versions 3.14.0, 3.15.0, 3.16.0, and 3.17.0. The flaw arises when the Contractors API feature is enabled—a feature that is rarely enabled and currently in private preview. This vulnerability allows contractor accounts, which should have limited access, to bypass intended authorization controls and gain unauthorized read access to the contents of internal repositories. This means that sensitive source code, proprietary information, or confidential project data stored in internal repositories could be exposed to unauthorized contractor users. The vulnerability does not require user interaction, has a network attack vector, and requires low privileges (contractor account access) but no authentication bypass or elevated privileges beyond that. The CVSS v4.0 score is 5.3, indicating a medium severity level. The issue was addressed and fixed in GitHub Enterprise Server versions 3.14.15, 3.15.10, 3.16.6, and 3.17.3. There are no known exploits in the wild at the time of publication, and the vulnerability is limited in scope to environments where the Contractors API feature is enabled. The vulnerability impacts confidentiality primarily, with limited impact on integrity or availability. Given that the Contractors API is a rarely enabled feature, the exposure is somewhat limited but critical for organizations that do enable this feature and rely on contractor accounts for development or collaboration.

For European organizations using GitHub Enterprise Server, especially those that enable the Contractors API feature, this vulnerability poses a risk of unauthorized disclosure of sensitive internal code repositories. This could lead to intellectual property theft, leakage of confidential business logic, or exposure of security-sensitive code that could be leveraged for further attacks. Organizations in sectors such as finance, technology, defense, and critical infrastructure, which often use private repositories for proprietary development, could be particularly impacted. The medium severity rating reflects that while the vulnerability requires a contractor account and the Contractors API feature to be enabled, the potential confidentiality breach could have significant business and compliance repercussions, including GDPR implications if personal data or sensitive information is exposed. The lack of known exploits reduces immediate risk but does not eliminate the threat, especially if attackers gain contractor credentials or if insider threats exist. The vulnerability does not affect availability or integrity directly but could indirectly impact trust and operational security.

European organizations should first verify if they are running affected versions of GitHub Enterprise Server (3.14.0, 3.15.0, 3.16.0, 3.17.0) and whether the Contractors API feature is enabled. If the feature is not enabled, the risk is minimal, but organizations should still monitor for any changes. For those with the feature enabled, immediate upgrade to patched versions (3.14.15, 3.15.10, 3.16.6, or 3.17.3 and above) is critical. Additionally, organizations should audit contractor account permissions and access logs to detect any unusual repository access patterns. Implement strict contractor account lifecycle management, including regular reviews and revocation of unnecessary access. Employ network segmentation and monitoring to detect anomalous API usage. Consider disabling the Contractors API feature if it is not essential. Finally, integrate this vulnerability into vulnerability management and incident response plans, ensuring rapid patch deployment and monitoring for potential exploitation attempts.