What is CVE-2026-118636?

CVE-2026-118636 is a critical-severity vulnerability in Apache Software Foundation Mina, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-10-31.

How severe is CVE-2026-118636?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Deserialization in Apache Software Foundation Mina

CVE-2026-118636

**UNSUPPORTED WHEN ASSIGNED** JavaNativeMessageDecoder in the MINA 3.0 codec module calls ObjectInputStream.readObject() on frame bytes with no class filter, so an application that puts it in front of an untrusted peer is open to gadget-chain RCE. As the 3.0.0 branch is inactive, we do not plan to release a version that fixes this issue. Users are recommended to use the latest Apache MINA 2.2.X branch.

Vulnerability class: Insecure Deserialization

Published 2026-10-31.

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.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Apache Software Foundation Mina

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

www.cve.org/CVERecord (third-party-advisory)
lists.apache.org/thread.html/h76nwcrkvsffhsk2kq6cjzc6srtnty7x (vendor-advisory)
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2026-118636?: CVE-2026-118636 is a critical-severity vulnerability in Apache Software Foundation Mina, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-10-31.
How severe is CVE-2026-118636?: Critical severity. CVSS v3 base score is 9.8 out of 10.