Red Hat Product Errata RHSA-2026:42733 - Security Advisory Issued: 2026-07-21 Updated: 2026-07-21 RHSA-2026:42733 - 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 8. 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: Information disclosure or denial of service via ungetwc function with specific wide character encodings (CVE-2026-5928) glibc: glibc: Out-of-bounds write via TSIG record processing (CVE-2026-5435) glibc: glibc: Application crash or uninitialized memory read via crafted DNS response (CVE-2026-6238) 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 8 x86_64 Red Hat Enterprise Linux for IBM z Systems 8 s390x Red Hat Enterprise Linux for Power, little endian 8 ppc64le Red Hat Enterprise Linux for ARM 64 8 aarch64 Red Hat CodeReady Linux Builder for x86_64 8 x86_64 Red Hat CodeReady Linux Builder for Power, little endian 8 ppc64le Red Hat CodeReady Linux Builder for ARM 64 8 aarch64 Red Hat CodeReady Linux Builder for IBM z Systems 8 s390x Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 8.10 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 8.10 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 8.10 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 8.10 s390x Fixes BZ - 2459854 - CVE-2026-5928 glibc: glibc: Information disclosure or denial of service via ungetwc function with specific wide character encodings BZ - 2463465 - CVE-2026-5435 glibc: glibc: Out-of-bounds write via TSIG record processing BZ - 2463539 - CVE-2026-6238 glibc: glibc: Application crash or uninitialized memory read via crafted DNS response CVEs CVE-2026-5435 CVE-2026-5928 CVE-2026-6238 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 8 SRPM glibc-2.28-251.el8_10.40.src.rpm SHA-256: 2ee88a75258a091820490a31ab9b2a706098dcb44a606b709bcaba6bc71da250 x86_64 compat-libpthread-nonshared-2.28-251.el8_10.40.x86_64.rpm SHA-256: 1541d66a412377250335c859c102095f76649aa2e92ce9429e3f2e14d7333d2c glibc-2.28-251.el8_10.40.i686.rpm SHA-256: 2f26cbd24d4e841915f8be634f6ddb0074c50a5f716a818373b52f0457cdcea9 glibc-2.28-251.el8_10.40.x86_64.rpm SHA-256: 671bb3257f869fe95219ac345942c50145dec73c7581217ada258ee15284c69a glibc-all-langpacks-2.28-251.el8_10.40.x86_64.rpm SHA-256: d1573cc88a29e5b80bd0bcb1240c72d53240ce68c87a04829e9690dd5ecd8a0a glibc-all-langpacks-debuginfo-2.28-251.el8_10.40.i686.rpm SHA-256: afaf1ce877b86df8f5ec04a8bad5838611c60c4abcf543aa6a3b2bc800b53a7b glibc-all-langpacks-debuginfo-2.28-251.el8_10.40.x86_64.rpm SHA-256: 0eefb212fa898ac8e9137f225e4dac387ce5793ac02f577869bc0108bf0e8cdc glibc-all-langpacks-debuginfo-2.28-251.el8_10.40.x86_64.rpm SHA-256: 0eefb212fa898ac8e9137f225e4dac387ce5793ac02f577869bc0108bf0e8cdc glibc-benchtests-debuginfo-2.28-251.el8_10.40.i686.rpm SHA-256: ab17626cbf2ed82e4a2a5fb1ce7bcf424a49224a7193f48e6cc03b113ea088f4 glibc-benchtests-debuginfo-2.28-251.el8_10.40.x86_64.rpm SHA-256: a0255312fac6ee4707bae473c37ad93795eae36ef2c4c36661287fc5a4f69709 glibc-benchtests-debuginfo-2.28-251.el8_10.40.x86_64.rpm SHA-256: a0255312fac6ee4707bae473c37ad93795eae36ef2c4c36661287fc5a4f69709 glibc-common-2.28-251.el8_10.40.x86_64.rpm SHA-256: 3f0564bcb8de216a8380da7186349efc9f551c88f8ece378dedde8f1780b373d glibc-common-debuginfo-2.28-251.el8_10.40.i686.rpm SHA-256: 6826f089a7112dce02acccc6607953907939a2ade45e6c5a8e7fe1af4d92505d glibc-common-debuginfo-2.28-251.el8_10.40.x86_64.rpm SHA-256: d28575354db7014d1f03a8edb9a1195c89a72a142fabd675fee0004bf9fb8cd6 glibc-common-debuginfo-2.28-251.el8_10.40.x86_64.rpm SHA-256: d28575354db7014d1f03a8edb9a1195c89a72a142fabd675fee0004bf9fb8cd6 glibc-debuginfo-2.28-251.el8_10.40.i686.rpm SHA-256: 7e477d3ee0335dc6e97cacdeb8a5bcb7834d735226d38cbdcfccbd2cc5fc5429 glibc-debuginfo-2.28-251.el8_10.40.x86_64.rpm SHA-256: 6694d8a5edf48805a7b8be2b9c981766fc37daae5dce2e5380652f677077f529 glibc-debuginfo-2.28-251.el8_10.40.x86_64.rpm SHA-256: 6694d8a5edf48805a7b8be2b9c981766fc37daae5dce2e5380652f677077f529 glibc-debugsource-2.28-251.el8_10.40.i686.rpm SHA-256: 33699eaae46bbe403d79d3d2ca15e0a5bd7440d7c6f69ab0d25b9fc9972457d4 glibc-debugsource-2.28-251.el8_10.40.x86_64.rpm SHA-256: c8b94a462ba03854c8cf486abcd49983e9e8fca7401d0ad36cfcfa3f034ba85f glibc-debugsource-2.28-251.el8_10.40.x86_64.rpm SHA-256: c8b94a462ba03854c8cf486abcd49983e9e8fca7401d0ad36cfcfa3f034ba85f glibc-devel-2.28-251.el8_10.40.i686.rpm SHA-256: 9d034919076ada96c49c9145aca3796587585d4f83a6eb491f41c726a3c4d7fd glibc-devel-2.28-251.el8_10.40.x86_64.rpm SHA-256: 6e951952aa437cc9f103d38d247a6fe358deb1902380bdf4de1f46aa4c69821e glibc-doc-2.28-251.el8_10.40.noarch.rpm SHA-256: d15e0bcf012fb8eaf8cb2cfd579834b3ee67274bcdcceb5447e9a09830f2de9c glibc-gconv-extra-2.28-251.el8_10.40.i686.rpm SHA-256: c729462cabf04bab1ed081b39f952ecec50c1b5a36937a6c9c9dc9d0ef2bbc6b glibc-gconv-extra-2.28-251.el8_10.40.x86_64.rpm SHA-256: d3c0d723773c5425845f374439bc7e37e6a8d037e6f44473c624a1e6fa90b693 glibc-gconv-extra-debuginfo-2.28-251.el8_10.40.i686.rpm SHA-256: ab9b24aebe37ee05d904eb20a9a27550800445fc67a4b00988356875dc4662ab glibc-gconv-extra-debuginfo-2.28-251.el8_10.40.x86_64.rpm SHA-256: 3dfcf4c82b61a0440cc55024f5060e32bb1f9463f1e79eda2dfc087bbf94c542 glibc-gconv-extra-debuginfo-2.28-251.el8_10.40.x86_64.rpm SHA-256: 3dfcf4c82b61a0440cc55024f5060e32bb1f9463f1e79eda2dfc087bbf94c542 glibc-headers-2.28-251.el8_10.40.i686.rpm SHA-256: e94bd4a9586b2efd6a0e3260237de5e005696052f331c1149cc1163906478e8e glibc-headers-2.28-251.el8_10.40.x86_64.rpm SHA-256: 188477bbd4003a9a44e52232048be5ed454cb1681ac67aa762fd5f74804b7ddb glibc-langpack-aa-2.28-251.el8_10.40.x86_64.rpm SHA-256: 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