Red Hat Product Errata RHSA-2026:12285 - Security Advisory Issued: 2026-04-30 Updated: 2026-04-30 RHSA-2026:12285 - 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 10. 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 10 x86_64 Red Hat Enterprise Linux for IBM z Systems 10 s390x Red Hat Enterprise Linux for Power, little endian 10 ppc64le Red Hat Enterprise Linux for ARM 64 10 aarch64 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 10 SRPM thunderbird-140.10.0-1.el10_1.src.rpm SHA-256: 16b8b90f319d11fb7197d7cdef055fde18caee7049e29eba4eea86d5622c2323 x86_64 thunderbird-140.10.0-1.el10_1.x86_64.rpm SHA-256: 24fa365a9e221a9a28cf25e90435578012525b8086bde4269f85e4732976f22d thunderbird-debuginfo-140.10.0-1.el10_1.x86_64.rpm SHA-256: 682ffef096279f3b31946f987bc8b1b3b65844c3827fcc0540cd76e60102a14a thunderbird-debugsource-140.10.0-1.el10_1.x86_64.rpm SHA-256: 8ce746a03fe18aba495c7c42038d1e0b783a490b61d31a42be051fbb21a21139 Red Hat Enterprise Linux for IBM z Systems 10 SRPM thunderbird-140.10.0-1.el10_1.src.rpm SHA-256: 16b8b90f319d11fb7197d7cdef055fde18caee7049e29eba4eea86d5622c2323 s390x thunderbird-140.10.0-1.el10_1.s390x.rpm SHA-256: 30f37d64f0ef47b5a76b58c26a0b7ad1fd3a5c3e2de51bcf8170bff041716e8b thunderbird-debuginfo-140.10.0-1.el10_1.s390x.rpm SHA-256: 0e997cccda0605ad06f42530c9e433394d92250dcbf1149f24b7890415e05b21 thunderbird-debugsource-140.10.0-1.el10_1.s390x.rpm SHA-256: 3535aae3d9460c00087cd0c100ad0820009226883522ef6cc142db271d339b6e Red Hat Enterprise Linux for Power, little endian 10 SRPM thunderbird-140.10.0-1.el10_1.src.rpm SHA-256: 16b8b90f319d11fb7197d7cdef055fde18caee7049e29eba4eea86d5622c2323 ppc64le thunderbird-140.10.0-1.el10_1.ppc64le.rpm SHA-256: cded53821cae5877adf826d132eba314e96b299071426b3f18c3cd8900ca13bb thunderbird-debuginfo-140.10.0-1.el10_1.ppc64le.rpm SHA-256: e6bab9a0b08b1df2feb31f8d98f707d7070d9f0ee3c18dc513183c0388c9793e thunderbird-debugsource-140.10.0-1.el10_1.ppc64le.rpm SHA-256: ba329bace0420d3776c7415d15d5e9adbdb68aa3a0951a4a1da45d87cdc92066 Red Hat Enterprise Linux for ARM 64 10 SRPM thunderbird-140.10.0-1.el10_1.src.rpm SHA-256: 16b8b90f319d11fb7197d7cdef055fde18caee7049e29eba4eea86d5622c2323 aarch64 thunderbird-140.10.0-1.el10_1.aarch64.rpm SHA-256: cb7bd442cca2f9e0ba939d0d40342592fad0d56e92eab5bc4295b32d54fbe7e1 thunderbird-debuginfo-140.10.0-1.el10_1.aarch64.rpm SHA-256: 5361e6ad458b4d6b1b3f57895cb0cb71d2939b610eca5016894f4acf473ba172 thunderbird-debugsource-140.10.0-1.el10_1.aarch64.rpm SHA-256: 820208a476636d4e966c9d1a9970d97f208811c0d0b1d05486357e65f7ac660b The Red Hat security contact is secalert@redhat.com . More contact details at https://access.redhat.com/security/team/contact/ .