CVE-2026-107938

CVE-2026-107938 is a critical-severity vulnerability in Apache Cxf with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-297.

Key facts

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.

Frequently asked questions

What is CVE-2026-107938?
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.
How severe is CVE-2026-107938?
CVE-2026-107938 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-107938 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-107938?
CVE-2026-107938 affects Apache Cxf. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-107938?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-107938 published?
CVE-2026-107938 was published on 2026-10-09 and last updated on 2026-10-16.

References

Affected products (1)

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