Apache MINA: AbstractIoBuffer.resolveClass() null-clazz Branch Skips acceptMatchers Filter — Full Object Deserialization RCE (take 2)
Title source: cnaExploitation Summary
EIP tracks 1 public exploit for CVE-2026-42779. PoCs published by dinosn.
AI-analyzed exploit summary This repository contains functional exploit code demonstrating CVE-2026-42779, a deserialization filter bypass in Apache MINA. The PoC shows how crafted type-0 descriptors bypass the acceptMatchers filter, enabling arbitrary class loading and potential RCE via gadget chains.
Description
The fix for CVE-2026-41635 was not applied to the 2.1.X and 2.2.X branches. Here was the original issue description: 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. The fix checks if the class is present in the accepted class filter before calling Class.forName(). Affected versions are Apache MINA 2.1.0 <= 2.1.11, and 2.2.0 <= 2.2.6. The problem is resolved in Apache MINA 2.1.12, and 2.2.7 by applying the classname allowlist earlier. Affected are applications using Apache MINA that call IoBuffer.getObject(). Applications using Apache MINA are advised to upgrade.
Exploits (1)
This repository contains functional exploit code demonstrating CVE-2026-42779, a deserialization filter bypass in Apache MINA. The PoC shows how crafted type-0 descriptors bypass the acceptMatchers filter, enabling arbitrary class loading and potential RCE via gadget chains.
References (1)
Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H