HTTP/2 transport accepts malformed framing-related headers in net/http
At a glance
Severity
HIGH 7.5
EPSS
EPSS 0.43 % · percentile 37 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
Go
NVD status
Awaiting Analysis
Description
Historically, we have been rather lax about malformed framing-related headers in our HTTP/2 implementation, as they cannot interfere with HTTP/2 framing. However, this makes it possible for our HTTP/2 implementation to forward responses containing such headers to an HTTP/1 client when acting as a reverse proxy. If the HTTP/1 client also does not behave strictly enough, this can result in response smuggling.
