Red Hat Product Errata RHSA-2026:14223 - Security Advisory Issued: 2026-05-06 Updated: 2026-05-06 RHSA-2026:14223 - Security Advisory Overview Updated Packages Synopsis Important: thunderbird 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 thunderbird is now available for Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions and Red Hat Enterprise Linux 8.8 Telecommunications Update Service. 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 Mozilla Thunderbird is a standalone mail and newsgroup client. Security Fix(es): libpng: libpng: Arbitrary code execution due to use-after-free vulnerability (CVE-2026-33416) libpng: libpng: Information disclosure and denial of service via out-of-bounds read/write in Neon palette expansion (CVE-2026-33636) thunderbird: firefox: Memory safety bugs fixed in Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2 (CVE-2026-5734) thunderbird: firefox: Memory safety bugs fixed in Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2 (CVE-2026-5731) firefox: thunderbird: Incorrect boundary conditions, integer overflow in the Graphics: Text component (CVE-2026-5732) 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 Update Support Extension 8.8 x86_64 Red Hat Enterprise Linux Server - TUS 8.8 x86_64 Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 8.8 ppc64le Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 8.8 x86_64 Fixes BZ - 2451805 - CVE-2026-33416 libpng: libpng: Arbitrary code execution due to use-after-free vulnerability BZ - 2451819 - CVE-2026-33636 libpng: libpng: Information disclosure and denial of service via out-of-bounds read/write in Neon palette expansion BZ - 2455897 - CVE-2026-5734 thunderbird: firefox: Memory safety bugs fixed in Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2 BZ - 2455901 - CVE-2026-5731 thunderbird: firefox: Memory safety bugs fixed in Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2 BZ - 2455908 - CVE-2026-5732 firefox: thunderbird: Incorrect boundary conditions, integer overflow in the Graphics: Text component CVEs CVE-2026-5731 CVE-2026-5732 CVE-2026-5734 CVE-2026-33416 CVE-2026-33636 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 Update Support Extension 8.8 SRPM thunderbird-140.9.1-1.el8_8.src.rpm SHA-256: 25e46253869adfa95625aeb6f7bbda91488201d9676325fa433716205be1ab33 x86_64 thunderbird-140.9.1-1.el8_8.x86_64.rpm SHA-256: 7948b6fef8dd8286a2d19d1dd0c14a7dc57b4c0366dc4dcf5dc6dc5eb3b5c634 thunderbird-debuginfo-140.9.1-1.el8_8.x86_64.rpm SHA-256: 2002a408022ea6c4b6a107e5f8170c67225f45d8687ff1a71479709df3504374 thunderbird-debugsource-140.9.1-1.el8_8.x86_64.rpm SHA-256: 5ecc889f440204cc7e75bb8b90c5b5ed23c087d069eb475ed5acd36a28e0f1ed Red Hat Enterprise Linux Server - TUS 8.8 SRPM thunderbird-140.9.1-1.el8_8.src.rpm SHA-256: 25e46253869adfa95625aeb6f7bbda91488201d9676325fa433716205be1ab33 x86_64 thunderbird-140.9.1-1.el8_8.x86_64.rpm SHA-256: 7948b6fef8dd8286a2d19d1dd0c14a7dc57b4c0366dc4dcf5dc6dc5eb3b5c634 thunderbird-debuginfo-140.9.1-1.el8_8.x86_64.rpm SHA-256: 2002a408022ea6c4b6a107e5f8170c67225f45d8687ff1a71479709df3504374 thunderbird-debugsource-140.9.1-1.el8_8.x86_64.rpm SHA-256: 5ecc889f440204cc7e75bb8b90c5b5ed23c087d069eb475ed5acd36a28e0f1ed Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 8.8 SRPM thunderbird-140.9.1-1.el8_8.src.rpm SHA-256: 25e46253869adfa95625aeb6f7bbda91488201d9676325fa433716205be1ab33 ppc64le thunderbird-140.9.1-1.el8_8.ppc64le.rpm SHA-256: f6aaf00f757e975efb2986a9cf49b62ee7944cab99e43af4d363297aec8d1730 thunderbird-debuginfo-140.9.1-1.el8_8.ppc64le.rpm SHA-256: a9787b76e3253519aed1c4175db73a4b2ffd82e4daaf6213a7404d6b7a035f2d thunderbird-debugsource-140.9.1-1.el8_8.ppc64le.rpm SHA-256: 90b50cbc6f9bfa638b7082a9235d30f7f171d721a6a9b12eb7ce5f6628f8c71d Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 8.8 SRPM thunderbird-140.9.1-1.el8_8.src.rpm SHA-256: 25e46253869adfa95625aeb6f7bbda91488201d9676325fa433716205be1ab33 x86_64 thunderbird-140.9.1-1.el8_8.x86_64.rpm SHA-256: 7948b6fef8dd8286a2d19d1dd0c14a7dc57b4c0366dc4dcf5dc6dc5eb3b5c634 thunderbird-debuginfo-140.9.1-1.el8_8.x86_64.rpm SHA-256: 2002a408022ea6c4b6a107e5f8170c67225f45d8687ff1a71479709df3504374 thunderbird-debugsource-140.9.1-1.el8_8.x86_64.rpm SHA-256: 5ecc889f440204cc7e75bb8b90c5b5ed23c087d069eb475ed5acd36a28e0f1ed The Red Hat security contact is secalert@redhat.com . More contact details at https://access.redhat.com/security/team/contact/ .