CVE-2026-59388 in CAPI
Summary
by MITRE • 10/30/2026
Cloud Controller (CAPI) leaks sensitive data into audit logs in multiple instances: custom buildpack credentials are exposed in audit events for app manifest application, creation, and updates; syslog drain URL credentials are exposed in user-provided service instance audit events; and service binding parameters are leaked in app manifest and service binding audit events.
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Analysis
by VulDB Data Team • 10/30/2026
The Cloud Controller API within the Cloud Foundry platform contains a critical information disclosure vulnerability that results in the unintended exposure of sensitive authentication credentials through its standard audit logging mechanisms. This flaw affects multiple operational contexts, including the application of custom buildpacks to applications via manifest updates or creation events, as well as the management of user-provided service instances and their associated bindings. The root cause lies in the failure to sanitize specific input fields before they are serialized into log entries for auditing purposes. When administrators or automated systems interact with these API endpoints to configure infrastructure components, the system captures the raw payload data without filtering out embedded secrets such as passwords, tokens, or connection strings that were provided by the user during configuration.
In the context of custom buildpacks, when an application manifest is used to apply a specific buildpack version or configuration, any credentials required for authentication with private repositories or external services are written directly into the audit log entries associated with app creation and update events. Similarly, for user-provided service instances, which often represent integrations with third-party systems like databases or messaging queues, the syslog drain URL configurations frequently contain embedded basic authentication credentials. These URLs are logged in plain text during instance management operations, exposing them to anyone with access to the log storage infrastructure. Furthermore, when creating service bindings that link applications to services, sensitive parameters such as API keys or database passwords included in the binding request body are also persisted in the audit trail without encryption or masking.
The operational impact of this vulnerability is severe due to the pervasive nature of logging systems within enterprise environments. Audit logs are typically centralized and accessible by a wide range of personnel, including DevOps engineers, security analysts, compliance auditors, and support staff who may not have elevated privileges for accessing application secrets but do require log visibility for troubleshooting or regulatory reporting purposes. The exposure of these credentials allows unauthorized individuals to gain access to external services, private repositories, or internal infrastructure components that rely on the leaked authentication data. This constitutes a significant breach of confidentiality and can lead to further compromise of the cloud environment if attackers monitor logs in real-time or retrieve historical log archives.
This vulnerability aligns with CWE-532, which describes information exposure through log files, where sensitive system information is written to an output medium that may be accessible to unauthorized actors. It also relates to CWE-798, involving the use of hardcoded credentials, although in this case, the issue is not hardcoding but rather the improper handling and logging of user-supplied secrets. From a threat modeling perspective using the MITRE ATT&CK framework, this behavior facilitates Initial Access through Credential Access techniques, specifically Log Collection or Data from Information Repositories, allowing adversaries to harvest valid credentials for lateral movement or privilege escalation within the cloud environment.
Mitigation strategies must focus on immediate remediation of logging configurations and long-term architectural changes to prevent secret leakage. Administrators should immediately review existing audit logs to identify any exposed credentials and rotate those secrets across all affected services and repositories. The Cloud Controller configuration requires updates to ensure that sensitive fields such as passwords, tokens, and connection strings are masked or redacted before being written to the audit log stream. This can be achieved by implementing strict input validation and sanitization routines within the API layer that strip out high-risk data patterns prior to serialization. Additionally, organizations should enforce least-privilege access controls on their logging infrastructure to ensure that only authorized security personnel with specific clearance levels can view raw application logs containing potential sensitive payloads. Future development cycles must prioritize secure coding practices that treat all user input as untrusted and apply consistent filtering rules across all data persistence layers, including audit trails, database records, and API responses.