Apache MINA: AbstractIoBuffer.resolveClass() null-clazz Branch Skips acceptMatchers Filter — Full Object Deserialization RCE
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 2.0.0 <= 2.0.27, 2.1.0 <= 2.1.10, and
2.2.0 <= 2.2.5.
The problem is resolved in Apache MINA 2.0.28, 2.1.11, and 2.2.6 by
applying the classname allowlist earlier.
Affected are applications using Apache MINA that call IoBuffer.getObject().
Applications using Apache MINA are advised to upgrade.
Problem Types
| Type | CWE ID | Description |
|---|
| CWE | CWE-502 | CWE-502 Deserialization of Untrusted Data |
Type: CWE
Description: CWE-502 Deserialization of Untrusted Data
Metrics
| Version | Base score | Base severity | Vector |
|---|
| 3.1 | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Version: 3.1
Base score: 9.8
Base severity: CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Timeline
| Event | Date |
|---|
| Initial reporting | 2026-04-17 00:00:00 |
Event: Initial reporting
Date: 2026-04-17 00:00:00