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HIGH7.5

GO-2026-6613

HTTP/1 server connection desynchronization after 2xx CONNECT response in net/http

Quick fix

GO-2026-6613 — stdlib: upgrade to the fixed version with the command below.

go get stdlib@v1.26.9

Details

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.

Are you affected?

Enter the version of the package you're using.

Affected packages

Go/stdlib
Introduced in: 0Fixed in: 1.26.9
Fixgo get stdlib@v1.26.9

References