RHSA-2026:55804MediumCVSS 5.4

Red Hat Security Advisory: nghttp2 security update

Published
August 17, 2026
Last Modified
August 18, 2026

🔗 CVE IDs covered (1)

CVE-2026-58055 →

📋 Description

CVE-2026-58055 — nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1 Upgrade requests

🎯 Affected products47

  • Red Hat Enterprise Linux BaseOS (v. 8)
  • Red Hat Enterprise Linux CRB (v. 8)
  • libnghttp2-0:1.33.0-6.el8_10.3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libnghttp2-0:1.33.0-6.el8_10.3.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libnghttp2-0:1.33.0-6.el8_10.3.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libnghttp2-0:1.33.0-6.el8_10.3.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libnghttp2-0:1.33.0-6.el8_10.3.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libnghttp2-debuginfo-0:1.33.0-6.el8_10.3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libnghttp2-debuginfo-0:1.33.0-6.el8_10.3.aarch64 as a component of Red Hat Enterprise Linux CRB (v. 8)
  • libnghttp2-debuginfo-0:1.33.0-6.el8_10.3.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libnghttp2-debuginfo-0:1.33.0-6.el8_10.3.i686 as a component of Red Hat Enterprise Linux CRB (v. 8)
  • libnghttp2-debuginfo-0:1.33.0-6.el8_10.3.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libnghttp2-debuginfo-0:1.33.0-6.el8_10.3.ppc64le as a component of Red Hat Enterprise Linux CRB (v. 8)
  • libnghttp2-debuginfo-0:1.33.0-6.el8_10.3.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libnghttp2-debuginfo-0:1.33.0-6.el8_10.3.s390x as a component of Red Hat Enterprise Linux CRB (v. 8)
  • libnghttp2-debuginfo-0:1.33.0-6.el8_10.3.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libnghttp2-debuginfo-0:1.33.0-6.el8_10.3.x86_64 as a component of Red Hat Enterprise Linux CRB (v. 8)
  • libnghttp2-devel-0:1.33.0-6.el8_10.3.aarch64 as a component of Red Hat Enterprise Linux CRB (v. 8)
  • libnghttp2-devel-0:1.33.0-6.el8_10.3.i686 as a component of Red Hat Enterprise Linux CRB (v. 8)
  • libnghttp2-devel-0:1.33.0-6.el8_10.3.ppc64le as a component of Red Hat Enterprise Linux CRB (v. 8)
  • libnghttp2-devel-0:1.33.0-6.el8_10.3.s390x as a component of Red Hat Enterprise Linux CRB (v. 8)
  • libnghttp2-devel-0:1.33.0-6.el8_10.3.x86_64 as a component of Red Hat Enterprise Linux CRB (v. 8)
  • nghttp2-0:1.33.0-6.el8_10.3.aarch64 as a component of Red Hat Enterprise Linux CRB (v. 8)
  • nghttp2-0:1.33.0-6.el8_10.3.ppc64le as a component of Red Hat Enterprise Linux CRB (v. 8)
  • nghttp2-0:1.33.0-6.el8_10.3.s390x as a component of Red Hat Enterprise Linux CRB (v. 8)
  • nghttp2-0:1.33.0-6.el8_10.3.src as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • nghttp2-0:1.33.0-6.el8_10.3.x86_64 as a component of Red Hat Enterprise Linux CRB (v. 8)
  • nghttp2-debuginfo-0:1.33.0-6.el8_10.3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • nghttp2-debuginfo-0:1.33.0-6.el8_10.3.aarch64 as a component of Red Hat Enterprise Linux CRB (v. 8)
  • nghttp2-debuginfo-0:1.33.0-6.el8_10.3.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • +17 more not shown

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: Configure your WAF or load balancer to drop incoming HTTP/1.1 requests that contain both Upgrade and Content-Length headers. This blocks the malformed traffic at the edge before it can reach the vulnerable proxy without impacting legitimate users.

🔗 References (4)