GO-2026-6089

Apply ReadHeaderTimeout when doing unencrypted HTTP/2 check in net/http

At a glance

Published
Updated
CVE
CVE-2026-56853
Aliases
BIT-golang-2026-56853

Description

When a server is configured to support unencrypted HTTP/2, it reads a few bytes from each new connection to see if they contain the HTTP/2 client preface. ReadHeaderTimeout is unexpectedly not being applied when doing this.

Affected packages

PackageVersions
Go · stdlibintroduced 0, fixed 1.25.13, introduced 1.26.0-0, fixed 1.26.6, introduced 1.27.0-0, fixed 1.27.0-rc.3

References

Sources

SourceLicence
OSV.devCC-BY 4.0 — Go Vulnerability Database