Red Hat Product Errata RHSA-2026:55992 - Security Advisory Issued: 2026-08-18 Updated: 2026-08-18 RHSA-2026:55992 - Security Advisory Overview Updated Packages Synopsis Important: mod_http2 security update Type/Severity Security Advisory: Important Red Hat Lightspeed patch analysis Identify and remediate systems affected by this advisory. View affected systems Topic An update for mod_http2 is now available for Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section. Description The mod_h2 Apache httpd module implements the HTTP2 protocol (h2+h2c) on top of libnghttp2 for httpd 2.4 servers. Security Fix(es): mod_http2: Apache HTTP Server: HTTP/2 DoS by Memory Increase (CVE-2025-53020) httpd: httpd: HTTP/2 Remote Denial of Service via compression bomb and Slowloris-style attack (CVE-2026-49975) httpd: mod_http2: Apache HTTP Server mod_http2: Use After Free vulnerability allows arbitrary code execution or denial of service. (CVE-2026-48913) httpd: Apache HTTP Server: Out-of-bounds Read in mod_headers and mod_mime (CVE-2026-43951) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Solution For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Affected Products Red Hat Enterprise Linux Server - AUS 9.4 x86_64 Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.4 ppc64le Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.4 x86_64 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.4 aarch64 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.4 s390x Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.4 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.4 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.4 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.4 s390x Fixes BZ - 2379343 - CVE-2025-53020 mod_http2: Apache HTTP Server: HTTP/2 DoS by Memory Increase BZ - 2485371 - CVE-2026-49975 httpd: httpd: HTTP/2 Remote Denial of Service via compression bomb and Slowloris-style attack BZ - 2486405 - CVE-2026-48913 httpd: mod_http2: Apache HTTP Server mod_http2: Use After Free vulnerability allows arbitrary code execution or denial of service. BZ - 2486415 - CVE-2026-43951 httpd: Apache HTTP Server: Out-of-bounds Read in mod_headers and mod_mime CVEs CVE-2025-53020 CVE-2026-43951 CVE-2026-48913 CVE-2026-49975 References https://access.redhat.com/security/updates/classification/#important Note: More recent versions of these packages may be available. Click a package name for more details. Red Hat Enterprise Linux Server - AUS 9.4 SRPM mod_http2-2.0.26-2.el9_4.3.src.rpm SHA-256: 9795386b9ed92693388690eebabbf9b0b97f40809f3116f18ad74175c211291f x86_64 mod_http2-2.0.26-2.el9_4.3.x86_64.rpm SHA-256: 7a1815c5eb6edbd2482ccd4ce73e3523a0fb0c75f9520a661d1170e0fe4547cf mod_http2-debuginfo-2.0.26-2.el9_4.3.x86_64.rpm SHA-256: 2907997c8c691af19c2f5645a3bc8da1d6c3e0c300c11b3f6743864e87bb9e80 mod_http2-debugsource-2.0.26-2.el9_4.3.x86_64.rpm SHA-256: d756542e6e1a679e16873852592a8eb77b67e41ce511811a051860a3648aeedc Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.4 SRPM mod_http2-2.0.26-2.el9_4.3.src.rpm SHA-256: 9795386b9ed92693388690eebabbf9b0b97f40809f3116f18ad74175c211291f ppc64le mod_http2-2.0.26-2.el9_4.3.ppc64le.rpm SHA-256: 3c47131980f71e5c90c92d2d179bf4bd9996099a829006e3e4b6cadf8d5b4c9a mod_http2-debuginfo-2.0.26-2.el9_4.3.ppc64le.rpm SHA-256: 280b87786581bfa6b478bc611d30d8b7c3819aa8798d0292c2b6a57f19bce493 mod_http2-debugsource-2.0.26-2.el9_4.3.ppc64le.rpm SHA-256: 2677f19817c4ba3cec01e0269dff50ab7f11d8ba3e597228c703be7df8974238 Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.4 SRPM mod_http2-2.0.26-2.el9_4.3.src.rpm SHA-256: 9795386b9ed92693388690eebabbf9b0b97f40809f3116f18ad74175c211291f x86_64 mod_http2-2.0.26-2.el9_4.3.x86_64.rpm SHA-256: 7a1815c5eb6edbd2482ccd4ce73e3523a0fb0c75f9520a661d1170e0fe4547cf mod_http2-debuginfo-2.0.26-2.el9_4.3.x86_64.rpm SHA-256: 2907997c8c691af19c2f5645a3bc8da1d6c3e0c300c11b3f6743864e87bb9e80 mod_http2-debugsource-2.0.26-2.el9_4.3.x86_64.rpm SHA-256: d756542e6e1a679e16873852592a8eb77b67e41ce511811a051860a3648aeedc Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.4 SRPM mod_http2-2.0.26-2.el9_4.3.src.rpm SHA-256: 9795386b9ed92693388690eebabbf9b0b97f40809f3116f18ad74175c211291f aarch64 mod_http2-2.0.26-2.el9_4.3.aarch64.rpm SHA-256: 9a7970af16d6c9c087274a0f14f7bcd1c42d6edc347de52067f455a85a12c14f mod_http2-debuginfo-2.0.26-2.el9_4.3.aarch64.rpm SHA-256: 78ce3ed966c17dc93502b3a1352ff27cdf575bd9e9d13029d0dc1121221a814a mod_http2-debugsource-2.0.26-2.el9_4.3.aarch64.rpm SHA-256: 51e2e51c274915f2243804823e42efe9bed32e6cd576e4b027556120a08d654a Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.4 SRPM mod_http2-2.0.26-2.el9_4.3.src.rpm SHA-256: 9795386b9ed92693388690eebabbf9b0b97f40809f3116f18ad74175c211291f s390x mod_http2-2.0.26-2.el9_4.3.s390x.rpm SHA-256: 050c111a4e2ccdf546c40deecafece2d792e7c21132bff08ddd3395a072e7df7 mod_http2-debuginfo-2.0.26-2.el9_4.3.s390x.rpm SHA-256: 9da87f2eccf64bbb8dc9df5a40bd942af7cc58367c63ff92347ae87179da2c1c mod_http2-debugsource-2.0.26-2.el9_4.3.s390x.rpm SHA-256: b581df533f7e5d019782448044f446a3a2622a968a2f21ab65b0b9e197a98b80 Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.4 SRPM mod_http2-2.0.26-2.el9_4.3.src.rpm SHA-256: 9795386b9ed92693388690eebabbf9b0b97f40809f3116f18ad74175c211291f x86_64 mod_http2-2.0.26-2.el9_4.3.x86_64.rpm SHA-256: 7a1815c5eb6edbd2482ccd4ce73e3523a0fb0c75f9520a661d1170e0fe4547cf mod_http2-debuginfo-2.0.26-2.el9_4.3.x86_64.rpm SHA-256: 2907997c8c691af19c2f5645a3bc8da1d6c3e0c300c11b3f6743864e87bb9e80 mod_http2-debugsource-2.0.26-2.el9_4.3.x86_64.rpm SHA-256: d756542e6e1a679e16873852592a8eb77b67e41ce511811a051860a3648aeedc Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.4 SRPM mod_http2-2.0.26-2.el9_4.3.src.rpm SHA-256: 9795386b9ed92693388690eebabbf9b0b97f40809f3116f18ad74175c211291f aarch64 mod_http2-2.0.26-2.el9_4.3.aarch64.rpm SHA-256: 9a7970af16d6c9c087274a0f14f7bcd1c42d6edc347de52067f455a85a12c14f mod_http2-debuginfo-2.0.26-2.el9_4.3.aarch64.rpm SHA-256: 78ce3ed966c17dc93502b3a1352ff27cdf575bd9e9d13029d0dc1121221a814a mod_http2-debugsource-2.0.26-2.el9_4.3.aarch64.rpm SHA-256: 51e2e51c274915f2243804823e42efe9bed32e6cd576e4b027556120a08d654a Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.4 SRPM mod_http2-2.0.26-2.el9_4.3.src.rpm SHA-256: 9795386b9ed92693388690eebabbf9b0b97f40809f3116f18ad74175c211291f ppc64le mod_http2-2.0.26-2.el9_4.3.ppc64le.rpm SHA-256: 3c47131980f71e5c90c92d2d179bf4bd9996099a829006e3e4b6cadf8d5b4c9a mod_http2-debuginfo-2.0.26-2.el9_4.3.ppc64le.rpm SHA-256: 280b87786581bfa6b478bc611d30d8b7c3819aa8798d0292c2b6a57f19bce493 mod_http2-debugsource-2.0.26-2.el9_4.3.ppc64le.rpm SHA-256: 2677f19817c4ba3cec01e0269dff50ab7f11d8ba3e597228c703be7df8974238 Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.4 SRPM mod_http2-2.0.26-2.el9_4.3.src.rpm SHA-256: 9795386b9ed92693388690eebabbf9b0b97f40809f3116f18ad74175c211291f s390x mod_http2-2.0.26-2.el9_4.3.s390x.rpm SHA-256: 050c111a4e2ccdf546c40deecafece2d792e7c21132bff08ddd3395a072e7df7 mod_http2-debuginfo-2.0.26-2.el9_4.3.s390x.rpm SHA-256: 9da87f2eccf64bbb8dc9df5a40bd942af7cc58367c63ff92347ae87179da2c1c mod_http2-debugsource-2.0.26-2.el9_4.3.s390x.rpm SHA-256: b581df533f7e5d019782448044f446a3a2622a968a2f21ab65b0b9e197a98b80 The Red Hat security contact is secalert@redhat.com . 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