CVE-2026-78605 is a vulnerability in Elasticsearch
Published on September 1, 2026
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') in Elasticsearch Leading to Information Disclosure
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') (CWE-444) in Elasticsearch can lead to information disclosure via HTTP Request Smuggling (CAPEC-33). Under specific proxy deployment configurations, a network attacker could obtain confidential responses intended for other authenticated users.
Vulnerability Analysis
CVE-2026-78605 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.
Weakness Type
What is a HTTP Request Smuggling Vulnerability?
When malformed or abnormal HTTP requests are interpreted by one or more entities in the data flow between the user and the web server, such as a proxy or firewall, they can be interpreted inconsistently, allowing the attacker to "smuggle" a request to one device without the other device being aware of it.
CVE-2026-78605 has been classified to as a HTTP Request Smuggling vulnerability or weakness.
Products Associated with CVE-2026-78605
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Affected Versions
Elasticsearch:- Version 8.18.0, <= 8.19.19 is affected.
- Version 9.0.0, <= 9.4.4 is affected.
- Version 9.5.0 is affected.