Deserialization in Apache Mina

CVE-2026-41635

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.

Vulnerability class: Insecure Deserialization

EPSS: 0.006 (48.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-41635?
CVE-2026-41635 is a critical-severity vulnerability in Apache Mina, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-04-27.
How severe is CVE-2026-41635?
Critical severity. CVSS v3 base score is 9.8 out of 10.