CVE-2026-94439
Published:October 08, 2026
Updated:October 13, 2026
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.
Affected Packages
https://github.com/golang/go.git (GITHUB):
Affected version(s) >=go1 <go1.26.9Fix Suggestion:
Update to version go1.26.9https://github.com/golang/go.git (GITHUB):
Affected version(s) >=go1.27.0 <go1.27.2Fix Suggestion:
Update to version go1.27.2github.com/golang/go (GO):
Affected version(s) >=go1.27.0 <go1.27.2Fix Suggestion:
Update to version go1.27.2github.com/golang/go (GO):
Affected version(s) >=go1 <go1.26.9Fix Suggestion:
Update to version go1.26.9Related Resources (5)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
EPSS
Base Score:
0.32