Resource exhaustion in Go programming language - CVE-2026-56853
Published: August 18, 2026
Vulnerability identifier: #VU144179
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-56853
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper timeout handling in net/http when processing new connections for unencrypted HTTP/2 support. A remote attacker can open a connection and withhold the expected HTTP/2 client preface bytes to cause a denial of service.
Only servers configured to support unencrypted HTTP/2 are vulnerable.
Affected software
Go programming language
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
golang (Red Hat package)
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
golang (Red Hat package)
How to mitigate CVE-2026-56853
Install security update from vendor's website.
Go programming language - addressed in versions 1.25.13, 1.26.6, 1.27.0 rc.3
golang (Red Hat package) - addressed in versions 1.26.7-1.el9_8, 1.26.7-1.el10_2
golang (Red Hat package) - addressed in versions 1.26.7-1.el9_8, 1.26.7-1.el10_2