CVE-2025-59474 is a security vulnerability identified in Jenkins, a widely used open-source automation server that facilitates continuous integration and continuous delivery (CI/CD). The vulnerability affects Jenkins versions 2.527 and earlier, including Long-Term Support (LTS) versions 2.516.2 and earlier. The core issue arises from the lack of a permission check in the sidepanel of a page that is intentionally accessible to users who do not have the Overall/Read permission. Specifically, this flaw allows attackers who lack Overall/Read permissions to enumerate agent names via the sidepanel executors widget. Agents (or nodes) in Jenkins are critical components that execute build jobs, and their names can reveal internal infrastructure details. Although the vulnerability does not grant direct access to sensitive data or control over Jenkins, it leaks information about the environment that could be leveraged in subsequent attacks, such as targeted exploitation or social engineering. The vulnerability does not require authentication, meaning that unauthenticated users can exploit it to gather information. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. The vulnerability is classified as an information disclosure issue due to the exposure of agent names without proper authorization checks.

For European organizations, the impact of CVE-2025-59474 primarily lies in the potential information disclosure that could aid attackers in reconnaissance activities. By enumerating agent names, attackers can gain insights into the internal Jenkins infrastructure, including the number and naming conventions of build agents, which may reflect organizational structure or project details. This information can facilitate more targeted attacks, such as phishing campaigns or attempts to exploit other vulnerabilities in specific agents or connected systems. While the vulnerability does not directly compromise confidentiality, integrity, or availability, it lowers the barrier for attackers to map the environment, increasing the risk of subsequent, more damaging attacks. Organizations with extensive Jenkins deployments, especially those using older versions, are at higher risk. Given Jenkins' widespread use in software development and DevOps pipelines across Europe, this vulnerability could affect a broad range of sectors, including finance, manufacturing, technology, and government agencies. The lack of authentication requirement increases the threat surface, as external attackers can attempt exploitation without credentials. However, since no known exploits are currently reported, the immediate risk is moderate but warrants prompt attention to prevent future exploitation.

To mitigate CVE-2025-59474, European organizations should: 1) Upgrade Jenkins to a version later than 2.527 or LTS later than 2.516.2 once patches are released, as this is the most effective way to eliminate the vulnerability. 2) In the interim, restrict access to Jenkins instances by enforcing network-level controls such as VPNs, IP whitelisting, or firewall rules to limit exposure to trusted users only. 3) Review and tighten Jenkins user permissions, ensuring that users have the minimum necessary privileges, and audit sidepanel access configurations to detect any unintended exposure. 4) Monitor Jenkins logs for unusual access patterns or attempts to access the sidepanel executors widget by unauthorized users. 5) Implement security best practices around Jenkins, including regular updates, use of security plugins that enhance access control, and segmentation of build agents to limit the impact of any reconnaissance. 6) Educate development and security teams about the importance of promptly applying security updates and monitoring for information disclosure risks.