CVE-2026-66909Network attack vectorHinoki check available

Code execution via unrestricted ObjectMessage deserialization

Published Aug 6, 2026 · Updated Aug 6, 2026

Unsafe deserialization in Apache CXF's JMS transport allows attackers to execute code through crafted inbound JMS ObjectMessages. The transport passes every inbound ObjectMessage body to native Java deserialization without restricting the permitted classes. The attacker must be able to place a message on the service's JMS destination, and code execution also requires a usable gadget class on the classpath; otherwise, a malicious object can interrupt the service.

CVSS severity9.8
Critical
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Unsafe deserialization in Apache CXF's JMS transport allows attackers to execute code through crafted inbound JMS ObjectMessages. The transport passes every inbound ObjectMessage body to native Java deserialization without restricting the permitted classes. The attacker must be able to place a message on the service's JMS destination, and code execution also requires a usable gadget class on the classpath; otherwise, a malicious object can interrupt the service.

The record

CVE
CVE-2026-66909
Published
Aug 6, 2026
Updated
Aug 6, 2026
Vendor
The Apache Software Foundation
Product
Apache CXF
Classifications
CWE-502, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.6.12
  2. Affected versionversion=4.0.0 <4.1.8
  3. Affected versionversion=4.2.0 <4.2.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache CXFversion=0 <3.6.12; version=4.0.0 <4.1.8; version=4.2.0 <4.2.3

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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