Red Hat Product Errata RHSA-2026:51034 - Security Advisory Issued: 2026-08-06 Updated: 2026-08-06 RHSA-2026:51034 - Security Advisory Overview Updated Packages Synopsis Important: postfix 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 postfix is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On. 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 postfix packages provide a Mail Transport Agent (MTA), which supports protocols like LDAP, SMTP AUTH (SASL), and TLS. Security Fix(es): postfix: buffer over-read via malformed enhanced status code (CVE-2026-43964) 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 - Extended Life Cycle Long Life 8.4 x86_64 Red Hat Enterprise Linux Server - AUS 8.4 x86_64 Fixes BZ - 2466488 - CVE-2026-43964 postfix: buffer over-read via malformed enhanced status code CVEs CVE-2026-43964 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 for x86_64 - Extended Life Cycle Long Life 8.4 SRPM postfix-3.5.8-1.el8_4.1.src.rpm SHA-256: a7705289e5a6de1e97b4aa28b748e86d249670ee7a5e6b0db7f2cf26f7748fd9 x86_64 postfix-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 376af471e3aac2c1c33cdb45ea671ea4ee83de6cfbb7dc62b3c9b020883c8e24 postfix-cdb-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 1ef7a5ecf758ca9358277b213edc57ff453fc1ea7e4bec8b7a19c69c7ab7f2aa postfix-cdb-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: b46c13f0c5c4fce0962c5628680a4a784fc3ca42cfe26781698c1e0f4512b5c1 postfix-cdb-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: b46c13f0c5c4fce0962c5628680a4a784fc3ca42cfe26781698c1e0f4512b5c1 postfix-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: cf9cec9c91d529d836b6b507abe87445b9030f0ea66d4c55fe922619397cd18d postfix-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: cf9cec9c91d529d836b6b507abe87445b9030f0ea66d4c55fe922619397cd18d postfix-debugsource-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 3013b33e5c758def6333d655626b73ebedf60cc13fa45c5c172586fbba96fd20 postfix-debugsource-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 3013b33e5c758def6333d655626b73ebedf60cc13fa45c5c172586fbba96fd20 postfix-ldap-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 990c43db48bd876c549f72766e3df7a05737d56e219baab1292be5b5f7291e0c postfix-ldap-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 8660d5b95159946d757858b84e1a631e08918dce40aa5475108c0d5ff3bd4a56 postfix-ldap-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 8660d5b95159946d757858b84e1a631e08918dce40aa5475108c0d5ff3bd4a56 postfix-lmdb-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 1f647f01f87fa571255bfa9c95863947069ddabfaada0ecc51ab8c96a055aad1 postfix-lmdb-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 1f647f01f87fa571255bfa9c95863947069ddabfaada0ecc51ab8c96a055aad1 postfix-mysql-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: d66b63468a00d9cff49fc7a067ae76a2903c382a43d98e130f381b26d001db8f postfix-mysql-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 8411989b6f403a4c110e492f03591703af28c7a7932cd7f8a5e64eb90e703d92 postfix-mysql-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 8411989b6f403a4c110e492f03591703af28c7a7932cd7f8a5e64eb90e703d92 postfix-pcre-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 39caba6075f5608be0b6cc6a245177dd8a2fb1c38db8c2d0f75371e2fdd74ada postfix-pcre-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: e0da5dfd7d5524423968f98773cce73c5e73862f0ec68468634a580bfa5879fa postfix-pcre-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: e0da5dfd7d5524423968f98773cce73c5e73862f0ec68468634a580bfa5879fa postfix-perl-scripts-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 56144a8459566f373eec7d79ebee68d7547808bcc00edb80628efb22ced3342e postfix-pgsql-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 1bd4bdc853ff94fb9e1d4633093cbb621775d01508925e2cf367940f360d11f2 postfix-pgsql-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 927ea893f124383a1e99a9b93aa47e1beb3d4dfbdb6b22c281c0421cea52f275 postfix-pgsql-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 927ea893f124383a1e99a9b93aa47e1beb3d4dfbdb6b22c281c0421cea52f275 postfix-sqlite-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 3e7362b279c36fc714728f385040c30b16a507314ef22fbfd6f399e2b55b3378 postfix-sqlite-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 2a068e460a49749514c756579665179bb1b786a76fea2b8837a864d6a9ea0b33 postfix-sqlite-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 2a068e460a49749514c756579665179bb1b786a76fea2b8837a864d6a9ea0b33 Red Hat Enterprise Linux Server - AUS 8.4 SRPM postfix-3.5.8-1.el8_4.1.src.rpm SHA-256: a7705289e5a6de1e97b4aa28b748e86d249670ee7a5e6b0db7f2cf26f7748fd9 x86_64 postfix-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 376af471e3aac2c1c33cdb45ea671ea4ee83de6cfbb7dc62b3c9b020883c8e24 postfix-cdb-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 1ef7a5ecf758ca9358277b213edc57ff453fc1ea7e4bec8b7a19c69c7ab7f2aa postfix-cdb-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: b46c13f0c5c4fce0962c5628680a4a784fc3ca42cfe26781698c1e0f4512b5c1 postfix-cdb-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: b46c13f0c5c4fce0962c5628680a4a784fc3ca42cfe26781698c1e0f4512b5c1 postfix-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: cf9cec9c91d529d836b6b507abe87445b9030f0ea66d4c55fe922619397cd18d postfix-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: cf9cec9c91d529d836b6b507abe87445b9030f0ea66d4c55fe922619397cd18d postfix-debugsource-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 3013b33e5c758def6333d655626b73ebedf60cc13fa45c5c172586fbba96fd20 postfix-debugsource-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 3013b33e5c758def6333d655626b73ebedf60cc13fa45c5c172586fbba96fd20 postfix-ldap-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 990c43db48bd876c549f72766e3df7a05737d56e219baab1292be5b5f7291e0c postfix-ldap-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 8660d5b95159946d757858b84e1a631e08918dce40aa5475108c0d5ff3bd4a56 postfix-ldap-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 8660d5b95159946d757858b84e1a631e08918dce40aa5475108c0d5ff3bd4a56 postfix-lmdb-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 1f647f01f87fa571255bfa9c95863947069ddabfaada0ecc51ab8c96a055aad1 postfix-lmdb-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 1f647f01f87fa571255bfa9c95863947069ddabfaada0ecc51ab8c96a055aad1 postfix-mysql-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: d66b63468a00d9cff49fc7a067ae76a2903c382a43d98e130f381b26d001db8f postfix-mysql-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 8411989b6f403a4c110e492f03591703af28c7a7932cd7f8a5e64eb90e703d92 postfix-mysql-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 8411989b6f403a4c110e492f03591703af28c7a7932cd7f8a5e64eb90e703d92 postfix-pcre-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 39caba6075f5608be0b6cc6a245177dd8a2fb1c38db8c2d0f75371e2fdd74ada postfix-pcre-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: e0da5dfd7d5524423968f98773cce73c5e73862f0ec68468634a580bfa5879fa postfix-pcre-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: e0da5dfd7d5524423968f98773cce73c5e73862f0ec68468634a580bfa5879fa postfix-perl-scripts-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 56144a8459566f373eec7d79ebee68d7547808bcc00edb80628efb22ced3342e postfix-pgsql-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 1bd4bdc853ff94fb9e1d4633093cbb621775d01508925e2cf367940f360d11f2 postfix-pgsql-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 927ea893f124383a1e99a9b93aa47e1beb3d4dfbdb6b22c281c0421cea52f275 postfix-pgsql-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 927ea893f124383a1e99a9b93aa47e1beb3d4dfbdb6b22c281c0421cea52f275 postfix-sqlite-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 3e7362b279c36fc714728f385040c30b16a507314ef22fbfd6f399e2b55b3378 postfix-sqlite-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 2a068e460a49749514c756579665179bb1b786a76fea2b8837a864d6a9ea0b33 postfix-sqlite-debuginfo-3.5.8-1.el8_4.1.x86_64.rpm SHA-256: 2a068e460a49749514c756579665179bb1b786a76fea2b8837a864d6a9ea0b33 The Red Hat security contact is secalert@redhat.com . 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