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CxfApplication · Apache

CVE-2026-66909

CRITICAL · 9.8 CVSS v3.1 Developing Published 2026-08-06
Fix available
A fix is available. Upgrade to 3.6.12 / 4.1.8 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click 13 days old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Apache CXF's JMS transport deserializes the body of any inbound JMS ObjectMessage using native Java deserialization, with no type restrictions in place. Any attacker able to place a message on the service's JMS destination can submit a malicious serialized object, leading to denial of service or, if a suitable gadget class is on the classpath, remote code execution. The fix disables ObjectMessage deserialization by default, with a configuration switch to re-enable it if needed. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · low confidence
Developing — this CVE was published recently and its authoritative NVD entry is still being established, so we're holding a technical summary until the source data settles rather than publish something unreliable. Re-checking after 2026-08-20.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
CxfApplication
Affected:< 3.6.12>= 4.0.0, < 4.1.8>= 4.2.0, < 4.2.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.6.12 / 4.1.8 / 4.2.3 or later
Fixed in 3.6.124.1.84.2.3
Recommended fix High confidence

Upgrade to CXF 3.6.12 (for 3.x branch), 4.1.8 (for 4.0.x-4.1.x branch), or 4.2.3 (for 4.2.x branch)

  1. Identify the current Apache CXF version in use by checking project dependencies (Maven pom.xml, Gradle build file, or library JAR metadata)
  2. Determine which version branch the current version belongs to: 3.x, 4.0.x-4.1.x, or 4.2.x
  3. For CXF 3.x versions (< 3.6.12): upgrade to version 3.6.12
  4. For CXF 4.0.x to 4.1.x versions (>= 4.0.0, < 4.1.8): upgrade to version 4.1.8
  5. For CXF 4.2.x versions (>= 4.2.0, < 4.2.3): upgrade to version 4.2.3
  6. After upgrading, verify that the application still functions correctly with the new CXF version
  7. If ObjectMessage deserialization is required for legitimate business logic, explicitly enable it via configuration using the new configuration switch (consult CXF documentation for the specific property)
Caveat Applications relying on automatic JMS ObjectMessage deserialization will need to either migrate to a safer format or explicitly enable the deserialization via configuration; thorough testing recommended after upgrade

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $3,550. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-66909 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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