Is CVE-2026-42778 actively exploited?

No active exploitation of CVE-2026-42778 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-42778 be exploited remotely?

Yes. CVE-2026-42778 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-42778?

CVE-2026-42778 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2026-42778

CWE-502Published: May 1, 2026· Updated: May 1, 2026

9.8

CVSS v3.1

EPSS:0.14%probability of exploitation in 30 daysPercentile:34.3th

Official Description

The fix for CVE-2026-41409 was not applied to the 2.1.X and 2.2.X branches. Here was the original issue description:

The fix for CVE-2024-52046 in Apache MINA AbstractIoBuffer.getObject() was incomplete. 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.

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

Affected versions are Apache MINA 2.1.0 <= 2.1.110, 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

NVD Source

Technical Analysis

CVE-2026-42778 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-502): Insecure deserialization vulnerabilities allow attackers to inject malicious objects during deserialization, potentially enabling remote code execution.