CVE-2026-42779

CRITICAL

Apache MINA: AbstractIoBuffer.resolveClass() null-clazz Branch Skips acceptMatchers Filter — Full Object Deserialization RCE (take 2)

Title source: cna
STIX 2.1

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.

Scores

CVSS v3 9.8
EPSS 0.0005
EPSS Percentile 14.0%
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-502
Status published
Products (2)
Apache Software Foundation/Apache MINA 2.1.X - 2.1.11
Apache Software Foundation/Apache MINA 2.2.X - 2.2.6
Published May 01, 2026
Tracked Since May 01, 2026