CVE-2026-58055: nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length

Overview

Severity

Medium (CVSS 5.4)

CVSS Vector

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

Exploit Status

Not Exploited

Patch Tuesday

2026-Jun

Released

2026-06-29

EPSS Score

0.20% (percentile: 10.2%)

Affected Products (1)

Other

• 21509-17084

Revision History

• 2026-06-29: Information published.