Red Hat Product Errata RHSA-2026:19469 - Security Advisory Issued: 2026-05-20 Updated: 2026-05-20 RHSA-2026:19469 - 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 9.4 Extended Update Support. 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): firefox: thunderbird: Incorrect boundary conditions in the Libraries component in NSS (CVE-2026-6772) firefox: thunderbird: Use-after-free in the JavaScript Engine component (CVE-2026-6754) firefox: thunderbird: Spoofing issue in the DOM: Core & HTML component (CVE-2026-6762) firefox: thunderbird: Incorrect boundary conditions in the WebRTC component (CVE-2026-6752) firefox: thunderbird: Other issue in the Storage: IndexedDB component (CVE-2026-6770) firefox: thunderbird: Invalid pointer in the JavaScript: WebAssembly component (CVE-2026-6757) firefox: thunderbird: Other issue in the Libraries component in NSS (CVE-2026-6767) firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.10, Thunderbird ESR 140.10, Firefox 150 and Thunderbird 150 (CVE-2026-6786) firefox: thunderbird: Incorrect boundary conditions in the WebRTC component (CVE-2026-6753) firefox: thunderbird: Use-after-free in the Widget: Cocoa component (CVE-2026-6759) firefox: thunderbird: Use-after-free in the WebRTC component (CVE-2026-6747) firefox: thunderbird: Information disclosure due to uninitialized memory in the Graphics: Canvas2D component (CVE-2026-6749) firefox: thunderbird: Incorrect boundary conditions in the Libraries component in NSS (CVE-2026-6766) firefox: thunderbird: Privilege escalation in the Networking component (CVE-2026-6761) firefox: thunderbird: Mitigation bypass in the File Handling component (CVE-2026-6763) firefox: thunderbird: Privilege escalation in the Graphics: WebRender component (CVE-2026-6750) firefox: thunderbird: Uninitialized memory in the Audio/Video: Web Codecs component (CVE-2026-6748) firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird ESR 140.10, Firefox 150 and Thunderbird 150 (CVE-2026-6785) firefox: thunderbird: Mitigation bypass in the DOM: Security component (CVE-2026-6771) firefox: thunderbird: Incorrect boundary conditions in the DOM: Device Interfaces component (CVE-2026-6764) firefox: thunderbird: Information disclosure in the Form Autofill component (CVE-2026-6765) firefox: thunderbird: Privilege escalation in the Debugger component (CVE-2026-6769) firefox: thunderbird: Uninitialized memory in the Audio/Video: Web Codecs component (CVE-2026-6751) firefox: thunderbird: Incorrect boundary conditions in the WebRTC: Networking component (CVE-2026-6776) firefox: thunderbird: Use-after-free in the DOM: Core & HTML component (CVE-2026-6746) 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 9.4 x86_64 Red Hat Enterprise Linux Server - AUS 9.4 x86_64 Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.4 s390x Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.4 ppc64le Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.4 aarch64 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 - 2460074 - CVE-2026-6772 firefox: thunderbird: Incorrect boundary conditions in the Libraries component in NSS BZ - 2460075 - CVE-2026-6754 firefox: thunderbird: Use-after-free in the JavaScript Engine component BZ - 2460076 - CVE-2026-6762 firefox: thunderbird: Spoofing issue in the DOM: Core & HTML component BZ - 2460078 - CVE-2026-6752 firefox: thunderbird: Incorrect boundary conditions in the WebRTC component BZ - 2460079 - CVE-2026-6770 firefox: thunderbird: Other issue in the Storage: IndexedDB component BZ - 2460085 - CVE-2026-6757 firefox: thunderbird: Invalid pointer in the JavaScript: WebAssembly component BZ - 2460086 - CVE-2026-6767 firefox: thunderbird: Other issue in the Libraries component in NSS BZ - 2460088 - CVE-2026-6786 firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.10, Thunderbird ESR 140.10, Firefox 150 and Thunderbird 150 BZ - 2460092 - CVE-2026-6753 firefox: thunderbird: Incorrect boundary conditions in the WebRTC component BZ - 2460094 - CVE-2026-6759 firefox: thunderbird: Use-after-free in the Widget: Cocoa component BZ - 2460095 - CVE-2026-6747 firefox: thunderbird: Use-after-free in the WebRTC component BZ - 2460096 - CVE-2026-6749 firefox: thunderbird: Information disclosure due to uninitialized memory in the Graphics: Canvas2D component BZ - 2460097 - CVE-2026-6766 firefox: thunderbird: Incorrect boundary conditions in the Libraries component in NSS BZ - 2460099 - CVE-2026-6761 firefox: thunderbird: Privilege escalation in the Networking component BZ - 2460101 - CVE-2026-6763 firefox: thunderbird: Mitigation bypass in the File Handling component BZ - 2460102 - CVE-2026-6750 firefox: thunderbird: Privilege escalation in the Graphics: WebRender component BZ - 2460103 - CVE-2026-6748 firefox: thunderbird: Uninitialized memory in the Audio/Video: Web Codecs component BZ - 2460104 - CVE-2026-6785 firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird ESR 140.10, Firefox 150 and Thunderbird 150 BZ - 2460105 - CVE-2026-6771 firefox: thunderbird: Mitigation bypass in the DOM: Security component BZ - 2460106 - CVE-2026-6764 firefox: thunderbird: Incorrect boundary conditions in the DOM: Device Interfaces component BZ - 2460107 - CVE-2026-6765 firefox: thunderbird: Information disclosure in the Form Autofill component BZ - 2460108 - CVE-2026-6769 firefox: thunderbird: Privilege escalation in the Debugger component BZ - 2460109 - CVE-2026-6751 firefox: thunderbird: Uninitialized memory in the Audio/Video: Web Codecs component BZ - 2460110 - CVE-2026-6776 firefox: thunderbird: Incorrect boundary conditions in the WebRTC: Networking component BZ - 2460112 - CVE-2026-6746 firefox: thunderbird: Use-after-free in the DOM: Core & HTML component CVEs CVE-2026-6746 CVE-2026-6747 CVE-2026-6748 CVE-2026-6749 CVE-2026-6750 CVE-2026-6751 CVE-2026-6752 CVE-2026-6753 CVE-2026-6754 CVE-2026-6757 CVE-2026-6759 CVE-2026-6761 CVE-2026-6762 CVE-2026-6763 CVE-2026-6764 CVE-2026-6765 CVE-2026-6766 CVE-2026-6767 CVE-2026-6769 CVE-2026-6770 CVE-2026-6771 CVE-2026-6772 CVE-2026-6776 CVE-2026-6785 CVE-2026-6786 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 9.4 SRPM thunderbird-140.10.0-1.el9_4.src.rpm SHA-256: caa030eaec8adaa6a3d1b44a5b80abd87bba053e4e73cddac0e92f65fd5b2ab0 x86_64 thunderbird-140.10.0-1.el9_4.x86_64.rpm SHA-256: 09b8d90e7483c93d241e3e8a555340a3d6d22744833d57db36e4e6e09e344e71 thunderbird-debuginfo-140.10.0-1.el9_4.x86_64.rpm SHA-256: 0156307f283ede483d5255f1c0ecdc107947cc8a90888b326f45bba00a98ccb5 thunderbird-debugsource-140.10.0-1.el9_4.x86_64.rpm SHA-256: da70370d60ea929e76100614dafbd128daf9bcb95c42b6148e2e368e2ce82f55 Red Hat Enterprise Linux Server - AUS 9.4 SRPM thunderbird-140.10.0-1.el9_4.src.rpm SHA-256: caa030eaec8adaa6a3d1b44a5b80abd87bba053e4e73cddac0e92f65fd5b2ab0 x86_64 thunderbird-140.10.0-1.el9_4.x86_64.rpm SHA-256: 09b8d90e7483c93d241e3e8a555340a3d6d22744833d57db36e4e6e09e344e71 thunderbird-debuginfo-140.10.0-1.el9_4.x86_64.rpm SHA-256: 0156307f283ede483d5255f1c0ecdc107947cc8a90888b326f45bba00a98ccb5 thunderbird-debugsource-140.10.0-1.el9_4.x86_64.rpm SHA-256: da70370d60ea929e76100614dafbd128daf9bcb95c42b6148e2e368e2ce82f55 Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.4 SRPM thunderbird-140.10.0-1.el9_4.src.rpm SHA-256: caa030eaec8adaa6a3d1b44a5b80abd87bba053e4e73cddac0e92f65fd5b2ab0 s390x thunderbird-140.10.0-1.el9_4.s390x.rpm SHA-256: 8b85cfe19856a434e9da142ee350ef4999224f53aaf02622cc015b61e624c9c9 thunderbird-debuginfo-140.10.0-1.el9_4.s390x.rpm SHA-256: 6c1bd9e99b5575ee6da767531807927af8127ccfa1052a78f3ca4b919d3d6a9c thunderbird-debugsource-140.10.0-1.el9_4.s390x.rpm SHA-256: 39633409ab297af384692a3d6f562c210d745702de2f48b743aa77becf79686d Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.4 SRPM thunderbird-140.10.0-1.el9_4.src.rpm SHA-256: caa030eaec8adaa6a3d1b44a5b80abd87bba053e4e73cddac0e92f65fd5b2ab0 ppc64le thunderbird-140.10.0-1.el9_4.ppc64le.rpm SHA-256: 4f2b6c0ab00bb44b05e30e6bc16acc55b211bbfcac0009eb46538383f15fcfc1 thunderbird-debuginfo-140.10.0-1.el9_4.ppc64le.rpm SHA-256: 5919f0b9d1da04e54bebc60665f48aace03