CVE-2026-56853: Apply ReadHeaderTimeout when doing unencrypted HTTP/2 check in net/http

Overview

Severity

High (CVSS 7.5)

CVSS Vector

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

Exploit Status

Not Exploited

Patch Tuesday

2026-Aug

Released

2026-08-20

Last Updated

2026-09-17

EPSS Score

0.57% (percentile: 45.1%)

Affected Products (6)

Other

• 21660-17084
• 21676-17084
• 19693-17084
• 21021-17084
• 21778-17084
• 21857-17084

Security Updates (1)

• Security Update

Revision History

• 2026-08-20: Information published.
• 2026-09-03: Information published.
• 2026-09-08: Information published.
• 2026-09-09: Information published.
• 2026-09-17: Information published.