Unknown severity · Source severity not reportedCVE-2026-107938

Apache CXF: The Netty HTTP client transport does not perform TLS hostname verification.CVE-2026-107938

Answer in brief

CVE-2026-107938 records a Unknown severity vulnerability in Apache CXF: The Netty HTTP client transport does not perform TLS hostname verification.. The current sources do not mark it as known exploited. The current feed maps Apache Software Foundation/org.apache.cxf:cxf-rt-transports-http-netty-client (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 9, 2026Updated Oct 9, 2026Source checked Oct 9, 2026First seen by HOL Oct 9, 2026Material review Oct 9, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Apache Software Foundation/org.apache.cxf:cxf-rt-transports-http-netty-client (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Apache Software Foundation/org.apache.cxf:cxf-rt-transports-http-netty-clientgeneric	>=4.2.0 <4.2.4 \|\| >=4.0.0 <4.1.9 \|\| >=0 <3.6.13	4.2.4, 4.1.9, 3.6.13

Recommended response

Check inventory. Check lockfiles and deployed manifests for Apache Software Foundation/org.apache.cxf:cxf-rt-transports-http-netty-client.
Review the reported fix. Update Apache Software Foundation/org.apache.cxf:cxf-rt-transports-http-netty-client to 4.2.4 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 9, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 9, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 9, 2026

Sources and claim methodology

Upstream source description

In Apache CXF, the Netty-based HTTP client transport (cxf-rt-transports-http-netty-client) did not verify that the hostname in the server’s TLS certificate matched the host being called. This applied over both HTTP/1.1 and HTTP/2, even when disableCNCheck was left at its default value of false. The certificate chain was validated against the configured trust store, but the endpoint’s identity was not. A network attacker able to intercept traffic could present any certificate trusted by the client, such as a publicly issued certificate for a domain they control, and impersonate the target service. They could then read or modify the exchanged messages, including credentials. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

Quoted source text, attributed separately from HOL analysis.