CVE-2026-66909: Apache CXF · Deserialization of Untrusted Data
Affects Apache CXFSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in 4.2.3 : patch Apache CXF as a priority.
Data as of 5 Nov 2026, 00:01 UTC
- EPSS
- 1.1% chance of exploitation in 30 days – higher than 66% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.2.3, 4.1.8, 3.6.12
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Upgrade Apache to 4.2.3, 4.1.8 or 3.6.12.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Apache Software FoundationApache CXF | Affected
| Fixed in
|
| Apache Software FoundationApache CXF | Affected
| Fixed in
|
| Apache Software FoundationApache CXF | Affected
| Fixed in
|
MavenApache Software Foundation/org.apache.cxf:cxf-rt-transports-jmspkg:maven/Apache Software Foundation/org.apache.cxf:cxf-rt-transports-jmsOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade Apache CXF to version 4.2.3, 4.1.8, or 3.6.12 where the vulnerability is fixed. The fix disables JMS ObjectMessage deserialization by default, mitigating the risk. If deserialization is required, it can be re-enabled via configuration with caution. Patch status is confirmed by vendor advisory information embedded in the description.
Description
Apache CXF's JMS transport component is vulnerable to deserialization of untrusted data via JMS ObjectMessage bodies. This vulnerability allows an attacker who can send messages to the JMS destination to submit malicious serialized objects, potentially causing denial of service or remote code execution if a suitable gadget class is present. The issue is fixed by disabling ObjectMessage deserialization by default and providing a configuration option to re-enable it if necessary. Users should upgrade to Apache CXF versions 4.2.3, 4.1.8, or 3.6.12 to address this vulnerability.