Google nethttp up to 1.26.8/1.27.1 HTTP Server request smuggling

Summaryinfo

A vulnerability was found in Google nethttp up to 1.26.8/1.27.1. It has been classified as problematic. This vulnerability affects unknown code of the component HTTP Server Handler. This manipulation causes request smuggling. This vulnerability appears as CVE-2026-94439. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as problematic was found in Google nethttp up to 1.26.8/1.27.1. Affected by this vulnerability is an unknown code block of the component HTTP Server Handler. The manipulation with an unknown input leads to a request smuggling vulnerability. The CWE definition for the vulnerability is CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. As an impact it is known to affect integrity. The summary by CVE is:

When an HTTP server handler sends a 2xx response to an HTTP/1 CONNECT request and returns without hijacking the connection, the server improperly continues to read and serve requests from the connection. Since a 2xx response to an HTTP/1 CONNECT converts the connection into a tunnel, the server should not treat the connection as continuing to contain HTTP. The impact of this misbehavior is mostly limited to potential request smuggling, where an intermediate proxy considers the data on the connection to be tunneled and the server considers it to be HTTP.

This vulnerability is known as CVE-2026-94439 since 09/21/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/09/2026).

Upgrading to version 1.26.9 or 1.27.2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-95428). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• Google

Name

• nethttp

Version

• 1.26.0
• 1.26.1
• 1.26.2
• 1.26.3
• 1.26.4
• 1.26.5
• 1.26.6
• 1.26.7
• 1.26.8
• 1.27.0
• 1.27.1

License

• free

Website

• Vendor: https://www.google.com/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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