CVE-2026-57302: Jenkins FitNesse Plugin Plaintext Password Storage Vulnerability

Technical summary

CVE-2026-57302 is a cleartext password storage vulnerability in Jenkins FitNesse Plugin ≤1.36. The plugin stores authentication credentials directly in config.xml files without encryption, violating secure credential management practices. The vulnerability is triggered when Extended Read permission is granted to Jenkins users or when an attacker gains file system access to the Jenkins controller. The CVSS 3.1 vector (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N) reflects network-adjacent attack surface, low complexity, requirement for valid Jenkins authentication, and confidentiality impact only. This maps to CWE-256 (Plaintext Storage of Password).

Business impact

Exposure of plaintext FitNesse plugin credentials can lead to lateral movement if those same credentials are reused across other systems or services. Teams relying on FitNesse for test automation may have embedded database, API, or application credentials in plugin configurations—leakage of these secrets increases insider threat risk and simplifies account takeover scenarios. Regulatory frameworks (PCI DSS, HIPAA, SOX) may classify unencrypted credential storage as a control failure, potentially triggering compliance findings. Remediation requires Jenkins controller access and should be prioritized if Extended Read is widely distributed or if sensitive test environments authenticate to production-like systems.

Affected systems

Jenkins instances running FitNesse Plugin version 1.36 or earlier are affected. Vulnerability exposure is limited to users who hold Extended Read permission on Jenkins jobs (or groups with that permission) and to local or administrative file system access to the Jenkins controller. The plugin must be installed and configured with FitNesse integration for the risk to manifest.

Exploitability

Exploitability is constrained by Jenkins access controls. An authenticated Jenkins user with Extended Read permission can view plaintext passwords stored in job config.xml without additional tools or lateral privileged escalation. File system access (e.g., SSH, RDP to the controller, container escape, or backup media) also enables exploitation without Jenkins authentication. No remote unauthenticated exploitation path exists. Complexity is low once access is obtained. The vulnerability is not tracked in the CISA KEV catalog, suggesting low real-world weaponization to date, but that does not reduce remediation priority if your organization has liberal Extended Read grants.

Remediation

Upgrade Jenkins FitNesse Plugin to a version later than 1.36 that implements encrypted credential storage. Verify the patched version through the Jenkins plugin update center or the official FitNesse plugin release notes. As an interim mitigation, restrict Extended Read permission to Jenkins administrators only and audit current permission assignments. Review all FitNesse job configurations for embedded credentials and migrate them to Jenkins Credentials Store, which provides encryption at rest. Rotate any plaintext credentials that may have been exposed.

Patch guidance

Consult the Jenkins FitNesse Plugin release notes on the Jenkins plugin repository to identify the first patched version after 1.36. Upgrade via the Jenkins web interface (Manage Jenkins → Manage Plugins → Updates) or by manual WAR/HPI deployment. After upgrade, restart Jenkins and verify that no plaintext passwords appear in new or updated job config.xml files. Consider implementing Jenkins Configuration as Code (JCasC) to codify secure credential handling policies and prevent regression.

Detection guidance

Search Jenkins controller file system for config.xml files and grep for plaintext password patterns (e.g., 'password=' not preceded by encryption markers). Audit Jenkins audit logs for unusual Extended Read permission grants or bulk config.xml access. Monitor Jenkins permission matrices for overly permissive roles. Use Jenkins plugin health scoring tools or security scanning plugins to flag outdated or vulnerable plugin versions. Implement file integrity monitoring on the Jenkins home directory to detect unauthorized credential file modification.

Why prioritize this

Although CVSS 3.1 scores this vulnerability as MEDIUM severity, the actual risk is context-dependent. If your Jenkins instance has tightly scoped Extended Read permissions and sensitive credentials are managed through Jenkins Credentials Store rather than plugin configuration, risk is lower. Conversely, if your organization grants Extended Read widely or embeds production credentials in FitNesse configurations, this warrants urgent remediation. Prioritize based on your credential hygiene practices and Jenkins access control posture. The vulnerability is not in CISA KEV, reducing immediate external threat pressure, but does not excuse remediation.

Risk score, explained

The CVSS 3.1 score of 4.3 (MEDIUM) reflects a localized, authenticated information disclosure with no impact on integrity or availability. The score assumes an attacker has valid Jenkins credentials and Extended Read permission, or file system access—a realistic but not trivial barrier. The vulnerability does not enable privilege escalation or remote code execution. However, the practical severity depends on whether exposed credentials grant access to sensitive environments; a plaintext credential for a production database or API is far more damaging than one for a test-only system. Risk assessment should incorporate credential sensitivity, Extended Read distribution, and current credential management practices.

Frequently asked questions