Red Hat Product Errata RHSA-2026:20597 - Security Advisory Issued: 2026-05-26 Updated: 2026-05-26 RHSA-2026:20597 - Security Advisory Overview Updated Packages Synopsis Moderate: glibc security update Type/Severity Security Advisory: Moderate Red Hat Lightspeed patch analysis Identify and remediate systems affected by this advisory. View affected systems Topic An update for glibc is now available for Red Hat Enterprise Linux 9. Red Hat Product Security has rated this update as having a security impact of Moderate. 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 glibc packages provide the standard C libraries (libc), POSIX thread libraries (libpthread), standard math libraries (libm), and the name service cache daemon (nscd) used by multiple programs on the system. Without these libraries, the Linux system cannot function correctly. Security Fix(es): glibc: glibc: Incorrect DNS response parsing via crafted DNS server response (CVE-2026-4437) glibc: glibc: Invalid DNS hostname returned via gethostbyaddr functions (CVE-2026-4438) glibc: glibc: Denial of Service via iconv() function with specific character sets (CVE-2026-4046) 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 for x86_64 9 x86_64 Red Hat Enterprise Linux for x86_64 - Extended Update Support 9.8 x86_64 Red Hat Enterprise Linux for IBM z Systems 9 s390x Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.8 s390x Red Hat Enterprise Linux for Power, little endian 9 ppc64le Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.8 ppc64le Red Hat Enterprise Linux for ARM 64 9 aarch64 Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.8 aarch64 Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.8 ppc64le Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.8 x86_64 Red Hat CodeReady Linux Builder for x86_64 9 x86_64 Red Hat CodeReady Linux Builder for Power, little endian 9 ppc64le Red Hat CodeReady Linux Builder for ARM 64 9 aarch64 Red Hat CodeReady Linux Builder for IBM z Systems 9 s390x Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support 9.8 x86_64 Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support 9.8 ppc64le Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support 9.8 s390x Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support 9.8 aarch64 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.8 aarch64 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.8 s390x Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.8 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.8 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.8 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.8 s390x Fixes BZ - 2449777 - CVE-2026-4437 glibc: glibc: Incorrect DNS response parsing via crafted DNS server response BZ - 2449783 - CVE-2026-4438 glibc: glibc: Invalid DNS hostname returned via gethostbyaddr functions BZ - 2453117 - CVE-2026-4046 glibc: glibc: Denial of Service via iconv() function with specific character sets RHEL-148252 - glibc: Fix incorrect setting of CXX variable in spec file CVEs CVE-2026-4046 CVE-2026-4437 CVE-2026-4438 References https://access.redhat.com/security/updates/classification/#moderate Note: More recent versions of these packages may be available. Click a package name for more details. Red Hat Enterprise Linux for x86_64 9 SRPM glibc-2.34-270.el9_8.src.rpm SHA-256: ac1dbcb022ceae7c6c59f7ea64f7f5e696f193158d10123ad7a9bf9344a7fa9b x86_64 glibc-2.34-270.el9_8.i686.rpm SHA-256: 3fc19a8522f176fc069a9dea21234c1d5d6b842c917948b7fde392e6e038e190 glibc-2.34-270.el9_8.x86_64.rpm SHA-256: 39e15c1eb3181970e467e4baeaf31673120890b7bb9dd97b311f1c1128b76d16 glibc-all-langpacks-2.34-270.el9_8.x86_64.rpm SHA-256: 1728da5f6d81be8a48967e2299bbb196d2b01c5951d8fc79b1cff20e810d81a9 glibc-benchtests-debuginfo-2.34-270.el9_8.i686.rpm SHA-256: 8ad71c3f04c649033637d27b2c5e2e42be6071e1239bfea89427a717de4d8fea glibc-benchtests-debuginfo-2.34-270.el9_8.i686.rpm SHA-256: 8ad71c3f04c649033637d27b2c5e2e42be6071e1239bfea89427a717de4d8fea glibc-benchtests-debuginfo-2.34-270.el9_8.x86_64.rpm SHA-256: 6ea78c60d23fc12b20d5909ed7f6ff81f6bbc3a6f6d4f4fb51ff63fb76f49e30 glibc-benchtests-debuginfo-2.34-270.el9_8.x86_64.rpm SHA-256: 6ea78c60d23fc12b20d5909ed7f6ff81f6bbc3a6f6d4f4fb51ff63fb76f49e30 glibc-common-2.34-270.el9_8.x86_64.rpm SHA-256: f63ee066c0942641ea683e499087a0e9b4fa80645387871ebef264bd51640567 glibc-common-debuginfo-2.34-270.el9_8.i686.rpm SHA-256: 31b60fbedfacb9e96239b338f5786f4a78863fee12b4f812a5e1302f722b9628 glibc-common-debuginfo-2.34-270.el9_8.i686.rpm SHA-256: 31b60fbedfacb9e96239b338f5786f4a78863fee12b4f812a5e1302f722b9628 glibc-common-debuginfo-2.34-270.el9_8.x86_64.rpm SHA-256: 02c9b44a3a7303e7fac3027f8c4ef02bb3f34528f03f0c5a7b77357e17b16434 glibc-common-debuginfo-2.34-270.el9_8.x86_64.rpm SHA-256: 02c9b44a3a7303e7fac3027f8c4ef02bb3f34528f03f0c5a7b77357e17b16434 glibc-debuginfo-2.34-270.el9_8.i686.rpm SHA-256: 45001fd7f098f4bc6fb9f25573d7075ce1721c6a0c2e8876e00ecde884b6bffc glibc-debuginfo-2.34-270.el9_8.i686.rpm SHA-256: 45001fd7f098f4bc6fb9f25573d7075ce1721c6a0c2e8876e00ecde884b6bffc glibc-debuginfo-2.34-270.el9_8.x86_64.rpm SHA-256: 648fe8041aecf02c39307f58366b37f313373a725364f503fe971ddd37b27a89 glibc-debuginfo-2.34-270.el9_8.x86_64.rpm SHA-256: 648fe8041aecf02c39307f58366b37f313373a725364f503fe971ddd37b27a89 glibc-debugsource-2.34-270.el9_8.i686.rpm SHA-256: 3e5ff0de7cc7f8a2c8854b4079636e83ee42130ea8b0392829308d04a744e0ec glibc-debugsource-2.34-270.el9_8.i686.rpm SHA-256: 3e5ff0de7cc7f8a2c8854b4079636e83ee42130ea8b0392829308d04a744e0ec glibc-debugsource-2.34-270.el9_8.x86_64.rpm SHA-256: 7ec064ddbbf685f0bac4c9c15133c3c9959ddea8f65f7d80afc327034438feb1 glibc-debugsource-2.34-270.el9_8.x86_64.rpm SHA-256: 7ec064ddbbf685f0bac4c9c15133c3c9959ddea8f65f7d80afc327034438feb1 glibc-devel-2.34-270.el9_8.i686.rpm SHA-256: b9f6570bf64437789e677524e1c6f3e4f0d0bdc21ae64b138b5c6ba4394e47bb glibc-devel-2.34-270.el9_8.x86_64.rpm SHA-256: ac596cb6c59f74558e4b9b3674abc34d79c9772c4165f5cda866c1c24c81f939 glibc-doc-2.34-270.el9_8.noarch.rpm SHA-256: 6b65164b61e3d3ab3dd9bad39f7ee04f1505e8f8becbceaff357ada546311ecb glibc-gconv-extra-2.34-270.el9_8.i686.rpm SHA-256: fa50f6d9e3d3ef1ccb50a9fa2cef56266ea15fdb1f9c20ced918431fbc494953 glibc-gconv-extra-2.34-270.el9_8.x86_64.rpm SHA-256: 8efaf43e7d522733399caa5df7cdaca13a3549c56ea918053b11fb3d898c0bab glibc-gconv-extra-debuginfo-2.34-270.el9_8.i686.rpm SHA-256: 65d3b5d80eeb8d2995ad4165b108fd3d53c00eb59ed72786f26afd658a9fa5e9 glibc-gconv-extra-debuginfo-2.34-270.el9_8.i686.rpm SHA-256: 65d3b5d80eeb8d2995ad4165b108fd3d53c00eb59ed72786f26afd658a9fa5e9 glibc-gconv-extra-debuginfo-2.34-270.el9_8.x86_64.rpm SHA-256: c9d7e0a6b1c16b8b6d0455f7e3418fc96ed6c2f3f7bd415c21286a1b96c10c67 glibc-gconv-extra-debuginfo-2.34-270.el9_8.x86_64.rpm SHA-256: c9d7e0a6b1c16b8b6d0455f7e3418fc96ed6c2f3f7bd415c21286a1b96c10c67 glibc-headers-2.34-270.el9_8.x86_64.rpm SHA-256: 0eab0982c27442a8e4acbd7b32a66757174482dcc183ef27412427f54f8f36d7 glibc-langpack-aa-2.34-270.el9_8.x86_64.rpm SHA-256: 90e3567c68f9d93e5db7935bc83aaf0b1064d5a10306ff02105efd4daeb6fe7b glibc-langpack-af-2.34-270.el9_8.x86_64.rpm SHA-256: b24b15bfef85583736a4e07a665b0e7fff0f59b7b5224138d3fb17c0fbfef333 glibc-langpack-agr-2.34-270.el9_8.x86_64.rpm SHA-256: 84230b0650293a9f64ea03b736e50e1b6f3fdb62b834c1af04b389e5bce054b9 glibc-langpack-ak-2.34-270.el9_8.x86_64.rpm SHA-256: 8c2785ea60b46f6950bf83ace5e4969ae2f6e37ce30470669b5875e075161493 glibc-langpack-am-2.34-270.el9_8.x86_64.rpm SHA-256: c3dc0bf9cb3c8661296ebbcadf7e15b2f8dd1e1e1e0c4cf8a43094b620d13a7f glibc-langpack-an-2.34-270.el9_8.x86_64.rpm SHA-256: 20e3d95d3a3eea45e9db7b532eeb051d8de282969659a18c5714f3a6bf83680b glibc-langpack-anp-2.34-270.el9_8.x86_64.rpm SHA-256: 4ce2931172222fc8cab9190f580f522ee3c4a2ede6603232778e51324f7b8693 glibc-langpack-ar-2.34-270.el9_8.x86_64.rpm SHA-256: 83b04db5caf532319673ba2e1dc2c228fa381a980cf32943325a72f21831b8a5 glibc-langpack-as-2.34-270.el9_8.x86_64.rpm SHA-256: 2652ad93697949b180ef0c43f884fdda171cbb9b0982e5913bdc25e1e20d8aca glibc-langpack-ast-2.34-270.el9_8.x86_64.rpm SHA-256: d22042bf167f08cad735755f3f5201ae2874b1c7ee94b87c6e5229e788395afc glibc-langpack-ayc-2.34-270.el9_8.x86_64.rpm SHA-256: 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