Apache MINA is widely recognized as a foundational network application framework, designed to help users easily develop high-performance and highly scalable network applications. By providing an abstract, event-driven asynchronous API over transports like TCP/IP and UDP/IP via Java NIO, it handles the heavy lifting of backend network communications.
However, the framework is currently facing a double-header of critical security threats. Two newly disclosed —CVE-2026-41635 and CVE-2026-41409—both carry a CVSS score of 9.8 and expose applications to Remote Code Execution (RCE) through unsafe object deserialization.
The first , tracked as CVE-2026-41635, is a classic logic bypass within the framework’s deserialization routine. Secure applications typically rely on an allowlist (in this case, the acceptMatchers filter) to verify incoming classes before processing them. However, researchers discovered a fatal flaw in the AbstractIoBuffer.resolveClass() method.
As the vulnerability report details, “Apache MINA’s AbstractIoBuffer.resolveClass() contains two branches, one of them (for static classes or primitive types) does not check the class at all, bypassing the classname allowlist and allowing arbitrary code to be executed”.
If a threat actor crafts a payload that routes through this unchecked branch, they can completely bypass the protective filters and execute arbitrary code with the privileges of the host application.
The second critical stems from an incomplete patch for a previous vulnerability (CVE-2024-52046) within AbstractIoBuffer.getObject().
In this scenario, the issue isn’t that the allowlist was bypassed, but rather that it was enforced too slowly. The security advisory explains that the “classname allowlist of classes allowed to be deserialized was applied too late after a static initializer in a class to be read might already have been executed”. Because Java executes static initializers when a class is loaded, an attacker could embed malicious code in a static block and have it execute before the framework ever realizes the class isn’t on the approved list.
These vulnerabilities affect any application using Apache MINA that actively calls the IoBuffer.getObject() method. The span multiple generations of the framework:
- 2.2.x Branch: 2.2.0 through 2.2.5
- 2.1.x Branch: 2.1.0 through 2.1.10
- 2.0.x Branch: 2.0.0 through 2.0.27
To remediate both issues, developers must apply the latest patches where the framework strictly applies the classname allowlist earlier in the process—verifying the class against the accepted filter before calling Class.forName(). Administrators are strongly advised to upgrade to versions 2.0.28, 2.1.11, or 2.2.6 immediately.
