CVE-2026-94439
HTTP/1 server connection desynchronization after 2xx CONNECT response in net/http
Description
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.
INFO
Published Date :
Oct. 8, 2026, 11:17 p.m.
Last Modified :
Oct. 8, 2026, 11:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Solution
- Update the HTTP server configuration.
- Ensure CONNECT responses do not allow further HTTP processing.
- Validate tunnel behavior with intermediate proxies.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-94439.
| URL | Resource |
|---|---|
| https://go.dev/cl/847311 | |
| https://go.dev/issue/81744 | |
| https://groups.google.com/g/golang-announce/c/U2fTuyDJznI | |
| https://pkg.go.dev/vuln/GO-2026-6613 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-94439 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-94439
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-94439 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-94439 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Oct. 08, 2026
Action Type Old Value New Value Added Description 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/94xxx/CVE-2026-94439.json">CVE-2026-94439</a> Added Reference https://go.dev/cl/847311 Added Reference https://go.dev/issue/81744 Added Reference https://groups.google.com/g/golang-announce/c/U2fTuyDJznI Added Reference https://pkg.go.dev/vuln/GO-2026-6613