Red Hat Product Errata RHSA-2026:19462 - Security Advisory Issued: 2026-05-20 Updated: 2026-05-20 RHSA-2026:19462 - 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 9.6 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 9.6 x86_64 Red Hat Enterprise Linux Server - AUS 9.6 x86_64 Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.6 s390x Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.6 ppc64le Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.6 aarch64 Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.6 ppc64le Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.6 x86_64 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.6 aarch64 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.6 s390x Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.6 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.6 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.6 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.6 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 9.6 SRPM thunderbird-140.10.0-1.el9_6.src.rpm SHA-256: 58667d96429a8ec840cc2e139ffa4357f7d9965bb582330790433b71a5d9d01f x86_64 thunderbird-140.10.0-1.el9_6.x86_64.rpm SHA-256: 37534a35857fdb152f389ecc63de58c22a12c05ed1a650cd14f4bca3b1e70014 thunderbird-debuginfo-140.10.0-1.el9_6.x86_64.rpm SHA-256: bf8eb5fd53fc734adf4ad14c89fed08344496d04fba6bd515bf2c3642838963a thunderbird-debugsource-140.10.0-1.el9_6.x86_64.rpm SHA-256: 0349decd504f1b940330b56d6c1a050bfeee690d19447c8cd975836adacf8532 Red Hat Enterprise Linux Server - AUS 9.6 SRPM thunderbird-140.10.0-1.el9_6.src.rpm SHA-256: 58667d96429a8ec840cc2e139ffa4357f7d9965bb582330790433b71a5d9d01f x86_64 thunderbird-140.10.0-1.el9_6.x86_64.rpm SHA-256: 37534a35857fdb152f389ecc63de58c22a12c05ed1a650cd14f4bca3b1e70014 thunderbird-debuginfo-140.10.0-1.el9_6.x86_64.rpm SHA-256: bf8eb5fd53fc734adf4ad14c89fed08344496d04fba6bd515bf2c3642838963a thunderbird-debugsource-140.10.0-1.el9_6.x86_64.rpm SHA-256: 0349decd504f1b940330b56d6c1a050bfeee690d19447c8cd975836adacf8532 Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.6 SRPM thunderbird-140.10.0-1.el9_6.src.rpm SHA-256: 58667d96429a8ec840cc2e139ffa4357f7d9965bb582330790433b71a5d9d01f s390x thunderbird-140.10.0-1.el9_6.s390x.rpm SHA-256: fb37d04bc17a9de43fc218fe1abfddf4c127d8c3748a7f347669a0f70e069ed9 thunderbird-debuginfo-140.10.0-1.el9_6.s390x.rpm SHA-256: 4b7665572cc8b387526eb05ef181f000b3be41fc2d341d6733fea7629ac0badf thunderbird-debugsource-140.10.0-1.el9_6.s390x.rpm SHA-256: 49e92037eb5155de8ae5ffd026beb02aa76bb60f3a4a9c04d435a765132b7e23 Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.6 SRPM thunderbird-140.10.0-1.el9_6.src.rpm SHA-256: 58667d96429a8ec840cc2e139ffa4357f7d9965bb582330790433b71a5d9d01f ppc64le thunderbird-140.10.0-1.el9_6.ppc64le.rpm SHA-256: 14dac33242e4f09b83c3e328a51ada5515da2538c19f74197909a3be47d6791e thunderbird-debuginfo-140.10.0-1.el9_6.ppc64le.rpm SHA-256: 52880ab42f40df76ba9b6150648982f17d0