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

Critical 9.1 Published 9 Oct 2026 Updated 15 Oct 2026

Apache CXF Netty client fails to verify TLS hostnames, allowing attackers to intercept and modify traffic via man-in-the-middle attacks.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-107938?

CVE-2026-107938 is a critical vulnerability in Apache Cxf, published on 9 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-297

Which versions are affected by CVE-2026-107938?

It affects 1 product.

Products include Apache Cxf.

How do I fix CVE-2026-107938?

Upgrade to a fixed version.

Is CVE-2026-107938 being exploited?

There is no known exploitation of CVE-2026-107938 in the wild and no public exploit code.

All Apache Cxf vulnerabilities

Sources

Also known as CLEANSTART-2026-YB05084, GHSA-vr34-m3cj-mgxg.