CVE-2026-43869

A flaw was found in Apache Thrift. This vulnerability involves improper validation of a certificate with a host mismatch, which could allow a remote attacker to bypass security checks. By presenting a specially crafted certificate, an attacker may impersonate a legitimate server or client. This could lead to a security bypass, potentially enabling unauthorized access or information disclosure.

Red Hat rates this vulnerability as Important because missing hostname verification allows an unauthenticated adversary in a man-in-the-middle position to subvert TLS authentication. Within Red Hat environments, Thrift is primarily utilized as an underlying library for inter-service communication across distributed microservices and telemetry pipelines. A network-positioned attacker can present a certificate issued for an arbitrary valid host to spoof trusted endpoints, thereby eavesdropping on or manipulating RPC traffic.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.