CVE-2026-42778 Apache MINA: CWE-502 Deserialization of Untrusted Data (take 2)
Attackers can execute arbitrary code via unsafe deserialization in Apache MINA if applications call IoBuffer.getObject(), requiring an upgrade to patched versions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42778?
CVE-2026-42778 is a critical unsafe deserialization vulnerability in Apache MINA, published on 1 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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
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 <= 2.1.110, 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
Weakness: CWE-502
Which versions are affected by CVE-2026-42778?
4 open source packages ship an affected version, including org.apache.mina:mina-core. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.apache.mina:mina-core Maven | From 2.1.0 | 2.1.12 |
org.apache.mina:mina-core Maven | From 2.1.0 | 2.1.12 |
org.apache.mina:mina-core Maven | From 2.2.0 | 2.2.7 |
org.apache.mina:mina-core Maven | From 2.2.0 | 2.2.7 |
Products include Apache Mina.
How do I fix CVE-2026-42778?
Upgrade org.apache.mina:mina-core to a fixed version for your release line: 2.1.12 or 2.2.7.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-42778 being exploited?
There is no known exploitation of CVE-2026-42778 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Apache MINA
- CVE-2024-52046 Apache MINA: MINA applications using unbounded deserialization may allow RCE
- CVE-2026-47065 Apache MINA: Critical Deserialization Allow-list Bypass via resolveProxyClass - ZDRES-232
- CVE-2026-42779 Apache MINA vulnerable to Deserialization of Untrusted Data (CVE-2026-41635 Incomplete Fix)
- CVE-2026-41409 Apache MINA: CWE-502 Deserialization of Untrusted Data
- CVE-2026-41635 Apache MINA vulnerable to Deserialization of Untrusted Data
Sources
Also known as CLEANSTART-2026-BH66717, CLEANSTART-2026-BN04389, CLEANSTART-2026-KZ81353, CLEANSTART-2026-VE14203, CLEANSTART-2026-YI69310, ECHO-a687-888d-d700 and 9 more.