CVE-2025-4979 is a medium-severity vulnerability affecting GitLab Community Edition (CE) and Enterprise Edition (EE) versions prior to 17.10.7, 17.11 before 17.11.3, and 18.0 before 18.0.1. The vulnerability stems from insufficient granularity in access control mechanisms related to Continuous Integration (CI) variables within the GitLab Web User Interface (WebUI). Specifically, an attacker with authenticated access and high privileges (as indicated by the CVSS vector requiring PR:H) can exploit this flaw by creating their own CI variable and then analyzing the HTTP response to infer or reveal masked or hidden CI variables that they did not author. These CI variables often contain sensitive information such as API keys, tokens, or credentials used during automated build and deployment processes. The vulnerability is classified under CWE-1220, which relates to insufficient granularity of access control, meaning that the system fails to enforce sufficiently fine-grained permissions on sensitive data exposure. Although the CVSS score is 4.9 (medium), the impact on confidentiality is high since sensitive CI variables can be exposed without user interaction. The attack does not require UI interaction beyond the creation of a variable and observation of the HTTP response, and it does not affect integrity or availability. No known exploits are reported in the wild as of the publication date. The lack of patch links suggests that fixes may be available in the referenced versions but are not linked here. Overall, this vulnerability allows an authenticated user with elevated privileges to bypass intended access restrictions on sensitive CI variables, potentially leading to credential leakage and subsequent compromise of automated pipelines or connected systems.

For European organizations relying on GitLab for their DevOps pipelines, this vulnerability poses a significant risk to the confidentiality of sensitive CI variables. Exposure of these variables can lead to unauthorized access to internal systems, cloud environments, or third-party services integrated into the CI/CD workflows. This can result in data breaches, unauthorized deployments, or lateral movement within the network. Organizations in sectors with strict data protection regulations such as GDPR (e.g., finance, healthcare, government) may face compliance risks and reputational damage if sensitive information is leaked. Since GitLab is widely used across Europe in both public and private sectors, the vulnerability could impact a broad range of organizations, especially those with complex CI/CD setups and multiple collaborators. The requirement for high privileges limits exploitation to users with elevated access, but insider threats or compromised accounts could leverage this flaw. The vulnerability does not impact system availability or integrity directly but can be a stepping stone for further attacks. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers often develop exploits after public disclosure.

European organizations should prioritize upgrading GitLab instances to versions 17.10.7, 17.11.3, 18.0.1, or later where this vulnerability is patched. Until upgrades are applied, organizations should audit user privileges to ensure that only trusted users have high-level access capable of creating CI variables. Implement strict role-based access controls (RBAC) and monitor for unusual activity related to CI variable creation or modification. Additionally, organizations should review and rotate any CI variables that may have been exposed, especially those granting access to critical systems or cloud resources. Employ network segmentation and monitoring to detect potential misuse of leaked credentials. Consider implementing additional encryption or secret management tools external to GitLab to reduce reliance on GitLab’s variable masking. Finally, maintain vigilance for any emerging exploit reports and apply security advisories promptly.