RHSA-2026:22551MediumCVSS 5.3

Red Hat Security Advisory: mod_http2 security update

Published
June 3, 2026
Last Modified
August 18, 2026

🔗 CVE IDs covered (1)

CVE-2025-53020 →

📋 Description

CVE-2025-53020 — mod_http2: Apache HTTP Server: HTTP/2 DoS by Memory Increase

🎯 Affected products14

  • Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-0:2.0.26-6.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-0:2.0.26-6.el9_8.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-0:2.0.26-6.el9_8.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-0:2.0.26-6.el9_8.src as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-0:2.0.26-6.el9_8.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-debuginfo-0:2.0.26-6.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-debuginfo-0:2.0.26-6.el9_8.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-debuginfo-0:2.0.26-6.el9_8.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-debuginfo-0:2.0.26-6.el9_8.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-debugsource-0:2.0.26-6.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-debugsource-0:2.0.26-6.el9_8.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-debugsource-0:2.0.26-6.el9_8.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-debugsource-0:2.0.26-6.el9_8.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)

✅ 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: The attack surface can be reduced by disabling HTTP/2 support in Apache. Follow the guidance in Red Hat KCS article to: - Remove h2 and h2c from the Protocols directive - Disable mod_http2 and mod_proxy_http2 modules (if not required) https://access.redhat.com/node/7056356

🔗 References (4)