CVE-2026-94439

high

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.

References

https://pkg.go.dev/vuln/GO-2026-6613

https://groups.google.com/g/golang-announce/c/U2fTuyDJznI

https://go.dev/issue/81744

https://go.dev/cl/847311

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-95428

Details

Source: Mitre, NVD

Published: 2026-10-08

Updated: 2026-10-09

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Severity: High

EPSS

EPSS: 0.00181