CVE-2026-26365 is a vulnerability classified under CWE-444 (Inconsistent Interpretation of HTTP Requests) affecting Akamai Ghost, a component deployed on Akamai CDN edge servers. The flaw stems from improper processing of custom hop-by-hop HTTP headers, particularly when the incoming HTTP request contains the header "Connection: Transfer-Encoding." This header is critical because it controls how message framing is interpreted between client, proxy, and origin servers. Akamai Ghost mishandles this header in certain processing paths, resulting in the forwarded request having invalid HTTP message framing. Consequently, the origin server may parse the request body incorrectly, enabling HTTP request smuggling attacks. Such attacks exploit discrepancies in how front-end and back-end servers parse HTTP requests, allowing attackers to bypass security controls, poison web caches, or conduct cross-user attacks. The vulnerability affects all versions of Akamai Ghost prior to the fix date of February 6, 2026. The CVSS v3.1 base score is 4.0, indicating medium severity due to network exploitability but requiring high attack complexity and no direct confidentiality or availability impact. No public exploits have been reported yet, but the potential for misuse exists given the widespread use of Akamai CDN services. The vulnerability highlights the importance of consistent HTTP header parsing and robust validation in CDN edge components.

The primary impact of CVE-2026-26365 is the potential for HTTP request smuggling attacks, which can lead to several security issues including bypassing security controls such as web application firewalls, poisoning of web caches, and unauthorized access to sensitive information through request manipulation. While the CVSS score indicates limited integrity impact and no direct confidentiality or availability loss, the scope change means that the vulnerability affects components beyond the immediate Akamai Ghost server, potentially impacting origin servers behind the CDN. Organizations using Akamai Ghost on their CDN edge servers may face risks of session hijacking, cache poisoning, or unauthorized request execution if attackers exploit this flaw. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially given the critical role of Akamai CDN in global internet infrastructure. The vulnerability could disrupt trust in content delivery and impact services relying on Akamai for secure and reliable HTTP request handling.

To mitigate CVE-2026-26365, organizations should apply patches or updates provided by Akamai as soon as they become available. In the interim, network defenders should implement strict validation and normalization of HTTP headers at the edge and origin servers to detect and block malformed or suspicious "Connection" and "Transfer-Encoding" headers. Deploying Web Application Firewalls (WAFs) with rules specifically designed to detect HTTP request smuggling patterns can help prevent exploitation. Monitoring HTTP traffic for anomalies in header usage and message framing inconsistencies is critical. Additionally, configuring origin servers to reject ambiguous or conflicting HTTP headers can reduce the attack surface. Collaboration with Akamai support to understand the deployment specifics and recommended configurations is advised. Finally, organizations should conduct security assessments and penetration tests focused on HTTP request smuggling to identify and remediate any residual risks.