CVE-2025-68925 is a vulnerability in the samrocketman jervis library, which is utilized for Job DSL plugin scripts and shared Jenkins pipeline libraries. The core issue stems from improper verification of the cryptographic signature in JSON Web Tokens (JWTs). Specifically, versions of jervis prior to 2.2 fail to validate that the JWT header explicitly specifies the algorithm as "alg":"RS256". This omission allows an attacker to craft a JWT with a manipulated or unexpected algorithm header, potentially bypassing signature verification. The vulnerability is classified under CWE-347, which concerns improper verification of cryptographic signatures. Because Jenkins pipelines often rely on JWTs for authentication and authorization of scripts or jobs, this flaw can lead to unauthorized pipeline execution or manipulation. The vulnerability is remotely exploitable without requiring authentication or user interaction, increasing its risk profile. The CVSS v4.0 score of 6.9 reflects a medium severity, considering the ease of exploitation and the impact on integrity and confidentiality. The vulnerability was publicly disclosed on January 13, 2026, and fixed in jervis version 2.2. No known exploits have been reported in the wild to date. Organizations using Jenkins with jervis versions below 2.2 should upgrade promptly to prevent potential exploitation. This vulnerability highlights the critical importance of strict cryptographic validation in CI/CD environments to maintain pipeline security and trustworthiness.

For European organizations, the impact of CVE-2025-68925 can be significant, especially those heavily reliant on Jenkins for continuous integration and continuous deployment (CI/CD) pipelines. Exploitation could allow attackers to bypass signature verification on JWTs, leading to unauthorized execution of pipeline scripts or injection of malicious code into build processes. This compromises the integrity of software development workflows, potentially introducing backdoors or vulnerabilities into production software. Confidentiality may also be affected if sensitive pipeline configurations or credentials are exposed or manipulated. The availability of CI/CD pipelines could be disrupted if malicious actors alter or disable automated jobs. Given the vulnerability requires no authentication or user interaction, attackers can remotely exploit it, increasing the risk of widespread attacks. The absence of known exploits in the wild currently reduces immediate risk, but the medium severity score and ease of exploitation necessitate urgent mitigation. European organizations in sectors such as finance, manufacturing, and technology, which depend on secure and reliable software delivery, are particularly at risk. Failure to address this vulnerability could lead to intellectual property theft, regulatory non-compliance, and reputational damage.

European organizations should take the following specific mitigation steps: 1) Immediately upgrade the samrocketman jervis library to version 2.2 or later, where the vulnerability is fixed. 2) Audit all Jenkins instances to identify usage of vulnerable jervis versions, including shared pipeline libraries and Job DSL scripts. 3) Implement strict validation of JWT tokens in Jenkins pipelines, ensuring that only tokens with the expected "alg":"RS256" header are accepted. 4) Restrict access to Jenkins pipeline configuration and script repositories to trusted personnel only, minimizing the risk of malicious token injection. 5) Monitor Jenkins logs for suspicious JWT usage or failed signature validations that could indicate exploitation attempts. 6) Employ network segmentation and firewall rules to limit exposure of Jenkins servers to untrusted networks. 7) Integrate security scanning tools into CI/CD pipelines to detect unauthorized changes or malicious code injections early. 8) Educate DevOps and security teams about the risks of improper cryptographic validation and best practices for secure pipeline management. These targeted actions go beyond generic advice by focusing on the specific vulnerability mechanics and the Jenkins environment context.