Apache MINA Arbitrary Code Execution Vulnerability

A critical arbitrary code execution vulnerability, CVE-2026-41635, has been identified in Apache MINA, an open-source network application framework. The vulnerability affects versions 2.0.0 through 2.0.27, 2.1.0 through 2.1.10, and 2.2.0 through 2.2.5. The flaw lies within the AbstractIoBuffer.resolveClass() method, where a branch lacks class validation, bypassing the classname allowlist. This allows remote attackers with low privileges to execute arbitrary code on systems using Apache MINA when the IoBuffer.getObject() method is called. Successful exploitation can lead to full system compromise, data exfiltration, and further attacks on interconnected systems. It is imperative that organizations using Apache MINA apply the necessary patches immediately to mitigate this critical risk.

Attack Chain

1. The attacker identifies a vulnerable application using Apache MINA versions 2.0.0-2.0.27, 2.1.0-2.1.10, or 2.2.0-2.2.5.
2. The attacker crafts a malicious payload containing serialized Java objects designed to exploit the class validation bypass in AbstractIoBuffer.resolveClass().
3. The attacker sends a network request to the vulnerable application that triggers the IoBuffer.getObject() method.
4. The IoBuffer.getObject() method deserializes the attacker-controlled data without proper class validation due to the flaw in AbstractIoBuffer.resolveClass().
5. The malicious serialized object executes arbitrary code within the context of the application.
6. The attacker gains control of the application server.
7. The attacker uses their access to move laterally within the network.
8. The attacker exfiltrates sensitive data or deploys ransomware.

Impact

Successful exploitation of CVE-2026-41635 allows attackers to execute arbitrary code on systems utilizing vulnerable versions of Apache MINA. This can lead to a full compromise of the affected system, including data exfiltration, denial of service, or further attacks on interconnected systems. The vulnerability is remotely exploitable with low privileges, increasing the potential for widespread impact across various sectors relying on Apache MINA for network communication. A successful attack poses a high risk to the confidentiality, integrity, and availability of affected systems and data.

Recommendation

• Immediately patch Apache MINA to the latest version to remediate CVE-2026-41635, as recommended by the vendor advisory (https://lists.apache.org/thread/1l91w1mqsb3lwfd504fs045ylxntt2tm).
• Implement network monitoring to detect suspicious activity related to deserialization attempts, as suggested by the CCB’s recommendation to upscale monitoring capabilities.
• Deploy the Sigma rule “Detect Apache MINA Vulnerable Class Deserialization Attempt” to identify potential exploitation attempts based on suspicious class names in network traffic.