CVE-2025-53666 is a security vulnerability affecting version 0.1 of the Jenkins Dead Man's Snitch Plugin. This plugin integrates Jenkins with the Dead Man's Snitch monitoring service, which alerts users if scheduled jobs fail to run. The vulnerability arises because the plugin stores Dead Man's Snitch tokens unencrypted within the job-specific config.xml files on the Jenkins controller. These tokens are sensitive credentials used to authenticate with the Dead Man's Snitch service. Because the tokens are stored in plaintext, any user with Item/Extended Read permission within Jenkins or anyone with access to the Jenkins controller's file system can view these tokens. This exposure risks unauthorized use of the tokens, potentially allowing attackers to manipulate monitoring alerts or gain further access to the Jenkins environment or related services. The vulnerability does not require user interaction for exploitation but does require some level of access to Jenkins or its underlying file system. There is no CVSS score assigned yet, and no known exploits have been reported in the wild. However, the risk is significant due to the sensitive nature of the credentials and the potential for lateral movement or disruption of CI/CD pipelines.

For European organizations relying on Jenkins for continuous integration and deployment, this vulnerability could lead to unauthorized disclosure of sensitive monitoring tokens. Attackers gaining access to these tokens could suppress alerts, masking failed or malicious job executions, which undermines operational security and incident detection. Additionally, if attackers leverage these tokens to interact with the Dead Man's Snitch service or Jenkins jobs, they could disrupt automated workflows, cause denial of service, or facilitate further compromise within the development environment. Given the critical role Jenkins plays in software delivery pipelines, exploitation could impact confidentiality, integrity, and availability of software builds and deployments. This is particularly concerning for sectors with strict compliance requirements such as finance, healthcare, and critical infrastructure prevalent in Europe. The vulnerability also increases insider threat risks, as users with limited Jenkins permissions could escalate their access to sensitive credentials.

European organizations should immediately audit Jenkins instances using the Dead Man's Snitch Plugin version 0.1 to identify exposed tokens in config.xml files. Upgrading to a patched version of the plugin, once available, is the most effective mitigation. Until then, restrict Jenkins Item/Extended Read permissions strictly to trusted users and review file system access controls on Jenkins controllers to prevent unauthorized access. Implement encryption or credential masking for sensitive tokens within Jenkins configurations if supported. Additionally, rotate Dead Man's Snitch tokens regularly to limit the window of exposure. Monitoring Jenkins logs and Dead Man's Snitch alerts for unusual activity can help detect exploitation attempts. Organizations should also consider isolating Jenkins controllers in segmented network zones with strict access controls to reduce attack surface. Finally, educate development and operations teams about the risks of storing sensitive credentials in plaintext and enforce secure credential management practices.