CVE-2026-86404: Deserialization of Untrusted Data
Vulnerability summary
CVE-2026-86404 is a high (CVSS 8.8) Deserialization of Untrusted Data vulnerability. EPSS estimates a 0.85% chance of exploitation in the next 30 days, higher than 57.6% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 6Timeline
- 07-09-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
EAP's Artemis deserialization configuration permits deserialization by default. ObjectMessage.getObject() uses ObjectInputStreamWithClassLoader, which implements allow-list/block-list filtering via its checkSecurity()/isTrustedType() method. However, by default both allow-list and block-list are empty. When the allow-list is empty (size == 0), isTrustedType() returns true for ALL classes. This means all classes are deserializable by default.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.85%
Chance of exploitation in the next 30 days
Percentile
58%
Versus all other CVEs
30-day change
+0.36 pp
From 0.50% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
No affected systems are recorded for this record.