CVE-2025-13426 is a vulnerability classified under CWE-913 (Improper Control of Dynamically-Managed Code Resources) affecting the JavaCallout policy in Google Cloud Apigee hybrid. The JavaCallout policy allows users to execute custom Java code within API proxies. This vulnerability arises because it is possible for an attacker to craft a malicious JavaCallout that injects a harmful object into the MessageContext, a runtime data structure used to pass information during API execution. By doing so, the attacker can execute arbitrary Java code and system commands on the Apigee runtime environment without requiring authentication or user interaction. This leads to remote code execution (RCE), which can be exploited to gain unauthorized access to sensitive data, move laterally within the victim’s network, and compromise backend systems connected to the API infrastructure. The vulnerability affects multiple versions of Apigee hybrid prior to the patched releases: Hybrid_1.11.2, 1.12.4, 1.13.3, 1.14.1, and OPDK versions 5202 and 5300. The CVSS 4.0 score of 8.7 indicates a high-severity issue with network attack vector, low attack complexity, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability. Although no known exploits are reported in the wild yet, the potential impact and ease of exploitation make this a critical concern for organizations using Apigee hybrid. The vulnerability highlights the risks of dynamically managed code execution environments where insufficient controls allow injection and execution of malicious code at runtime.

For European organizations, this vulnerability poses significant risks due to the widespread adoption of Google Cloud services and API management platforms like Apigee hybrid. Successful exploitation can lead to unauthorized disclosure of sensitive personal and corporate data, violating GDPR and other data protection regulations. The ability to execute arbitrary code and commands enables attackers to move laterally within enterprise networks, potentially compromising critical backend systems and services. This can disrupt business operations, cause data breaches, and damage organizational reputation. Given the high integration of APIs in digital services across finance, healthcare, government, and telecommunications sectors in Europe, the impact could be severe. Additionally, the lack of required authentication or user interaction lowers the barrier for attackers, increasing the likelihood of exploitation if patches are not applied promptly. The threat also raises concerns about supply chain security for organizations relying on Apigee hybrid for API management and integration.

Organizations should immediately identify all deployments of Google Cloud Apigee hybrid and verify their versions against the patched releases (Hybrid_1.11.2+, 1.12.4+, 1.13.3+, 1.14.1+, OPDK_5202+, OPDK_5300+). Applying these updates is the primary mitigation step. Additionally, restrict the use of JavaCallout policies to trusted developers and enforce code review processes to detect potentially malicious code. Implement runtime monitoring and anomaly detection on API proxies to identify unusual Java execution or system command invocations. Employ network segmentation to limit lateral movement in case of compromise. Use strong access controls and audit logging to track changes and usage of JavaCallout policies. Consider disabling JavaCallout policies if not required. Regularly review and update API security configurations and conduct penetration testing focused on API runtime environments. Finally, maintain incident response readiness to quickly contain and remediate any exploitation attempts.