CVE-2026-65325 in Traffic Server
Summary
by MITRE • 07/29/2026
Apache Traffic Server reuses multiplexed HTTP/2 origin connections without verifying the server certificate covers the new request hostname.
This issue affects Apache Traffic Server: from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3.
Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.
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Analysis
by VulDB Data Team • 07/29/2026
The vulnerability in Apache Traffic Server represents a critical security flaw that undermines the integrity of HTTP/2 connection handling and certificate validation processes. This issue stems from the software's improper verification of server certificates when reusing multiplexed connections for different hostnames, creating a significant attack surface that can be exploited by malicious actors to perform man-in-the-middle attacks or redirect traffic to unauthorized servers.
The technical implementation flaw occurs within the HTTP/2 connection management subsystem where the system maintains persistent connections to origin servers. When multiple requests are multiplexed over a single connection, the server certificate validation process fails to re-verify that the certificate presented by the origin server is valid for the specific hostname being requested. This behavior violates fundamental security principles of certificate validation and trust establishment, as established by industry standards such as cwe-295 which addresses improper certificate validation.
The operational impact of this vulnerability extends beyond simple connection reuse scenarios and creates a pathway for attackers to exploit the trust relationship between the proxy server and origin servers. An attacker who can manipulate network traffic or compromise an intermediate system could potentially redirect requests to malicious hosts while maintaining the appearance of legitimate communication, as the system would not validate that the certificate matches the requested hostname during subsequent requests on reused connections.
This vulnerability directly maps to attack techniques described in the mitre ATT&CK framework under initial access and credential access phases, specifically targeting network protocol manipulation and trust relationship exploitation. The flaw enables attackers to bypass security controls designed to ensure certificate authenticity and hostname validation, potentially leading to data interception, unauthorized access to sensitive information, or complete compromise of the communication channel.
The affected versions span multiple release branches including 9.0.0 through 9.2.14 and 10.0.0 through 10.1.3, indicating this represents a widespread issue across the Apache Traffic Server product line that has persisted for several releases. Organizations utilizing these vulnerable versions face significant risk as the flaw allows for certificate validation bypass without requiring elevated privileges or complex attack vectors.
Mitigation efforts should focus on immediate upgrade to patched versions 9.2.15 and 10.1.4, which implement proper hostname verification for reused connections. Additionally, administrators should consider implementing additional monitoring controls to detect unusual connection patterns or certificate mismatches within their network traffic. Organizations may also benefit from deploying network segmentation strategies and enhanced certificate monitoring solutions to detect potential exploitation attempts while awaiting the upgrade process.
The vulnerability demonstrates how modern web proxy implementations must maintain rigorous security validation even when optimizing for performance through connection reuse, highlighting the critical importance of certificate validation in all network communication scenarios. This issue serves as a reminder that performance optimizations should never compromise fundamental security guarantees, particularly in systems handling sensitive traffic and maintaining trust relationships with multiple parties.