Vulnerability in Apache Software Foundation Apache CXF

[ Why it matters ]Priority signals

• Critical severity: CVSS 9.1

[ Description ]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.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund8 Oct 2026WID-SEC-2026-3824

  Apache CXF: Multiple vulnerabilities Translated from German

  CVE-2026-78384CVE-2026-97791CVE-2026-108039+7 more CVEs

[ References ]References

• lists.apache.org/thread.html/ljsjsq1foyjy1v5o22oncw80twx7k2tcIssue TrackingVendor Advisory
• www.openwall.com/lists/oss-security/2026/10/09/13Mailing ListThird Party Advisory