Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-42778 is a critical-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Apache Mina. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 48th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-42778 is a vulnerability in Apache MINA stemming from an incomplete fix for CVE-2026-41409, which itself addressed an earlier incomplete patch for CVE-2024-52046 in the AbstractIoBuffer.getObject() method. The issue occurs because the classname allowlist for deserialization is applied too late, potentially allowing static initializers in untrusted classes to execute during object deserialization. Affected versions include Apache MINA 2.1.0 through 2.1.11 and 2.2.0 through 2.2.6, impacting applications that use Apache MINA and invoke the IoBuffer.getObject() method.
Attackers can exploit this remotely over the network with low complexity, requiring no privileges or user interaction, as indicated by the CVSS 3.1 score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). A remote unauthenticated attacker could send malicious serialized data to a vulnerable application, triggering execution of static initializers in a gadget class before allowlist validation, leading to arbitrary code execution and high impacts on confidentiality, integrity, and availability (CWE-502: Deserialization of Untrusted Data).
The Apache advisory recommends upgrading to Apache MINA 2.1.12 or 2.2.7, where the classname allowlist is applied earlier in the deserialization process to prevent premature static initializer execution. Details are available in the Apache mailing list thread at https://lists.apache.org/thread/fhlx5k91hrkgyzh7yk1nghrn3k27gxy0.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-26492
Vulnerability Data
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…
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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
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can uncover deserialization flaws before deployment.
Input validation directly stops deserialization of untrusted data by ensuring inputs are valid before processing.
Engineering principles such as safe deserialization and input sanitization structurally prevent the weakness from being introduced.
Integrity verification tools can detect malformed or tampered serialized data after the fact.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-02 addresses only post-deployment updates/patching and cannot prevent introduction of unsafe deserialization code, yet it can remediate some instances when the flaw exists in outdated libraries or components.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing includes validation of deserialization routines and the use of untrusted data, reducing the likelihood that unsafe object reconstruction will be deployed.
Requiring vetted libraries, regular updates and SAST before release reduces the likelihood that deserialization logic will accept and act on attacker-controlled serialized objects.
Regular scanning of third-party libraries and timely patching reduce the likelihood that unsafe deserialization vulnerabilities remain active.
Mandatory malware scanning of data received over networks or storage media intercepts malicious serialized payloads before they are deserialized by the target application.