CVE-2026-56853CWE-770denial-of-service

CVE-2026-56853

High · published August 14, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
46.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00568 · 46.3th percentile
Weakness
CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-08-14T02:17Z
References (4)
https://go.dev/cl/795540 · [email protected]https://go.dev/issue/80205 · [email protected]https://groups.google.com/g/golang-announce/c/94pEornpRlI · [email protected]https://pkg.go.dev/vuln/GO-2026-6089 · [email protected]
EPSS history
Timeline
  • 13 AUG 21:58Z
    Apply ReadHeaderTimeout when doing unencrypted HTTP/2 check in net/http
    cvelistv5