Red Hat Product Errata RHSA-2026:22325 - Security Advisory Issued: 2026-06-01 Updated: 2026-06-01 RHSA-2026:22325 - 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: Incorrect boundary conditions in the JavaScript Engine: JIT component (CVE-2026-8388) firefox: Other issue in the JavaScript Engine component (CVE-2026-8391) firefox: Sandbox escape in the Profile Backup component (CVE-2026-8401) firefox: Integer overflow in the Networking: JAR component (CVE-2026-8956) firefox: Memory safety bugs fixed in Firefox ESR 115.36, Firefox ESR 140.11 and Firefox 151 (CVE-2026-8975) firefox: Privilege escalation in the DOM: Workers component (CVE-2026-8955) firefox: Denial-of-service due to invalid pointer in the Audio/Video: Web Codecs component (CVE-2026-8968) firefox: Incorrect boundary conditions, integer overflow in the Audio/Video component (CVE-2026-8954) firefox: Information disclosure, sandbox escape in the Security: Process Sandboxing component (CVE-2026-8958) firefox: Incorrect boundary conditions in the Audio/Video: Web Codecs component (CVE-2026-8946) firefox: Privilege escalation in the Security component (CVE-2026-8970) firefox: Same-origin policy bypass in the Networking: HTTP component (CVE-2026-8950) firefox: Memory safety bugs fixed in Firefox ESR 140.11 and Firefox 151 (CVE-2026-8974) firefox: Sandbox escape due to use-after-free in the Disability Access APIs component (CVE-2026-8953) firefox: Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component (CVE-2026-8959) firefox: Spoofing issue in the Form Autofill component (CVE-2026-8961) firefox: Use-after-free in the DOM: Bindings (WebIDL) component (CVE-2026-8947) firefox: Mitigation bypass in the DOM: Security component (CVE-2026-8962) firefox: Privilege escalation in the Enterprise Policies component (CVE-2026-8957) 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 x86_64 - Extended Update Support 10.2 x86_64 Red Hat Enterprise Linux for IBM z Systems 10 s390x Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.2 s390x Red Hat Enterprise Linux for Power, little endian 10 ppc64le Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.2 ppc64le Red Hat Enterprise Linux for ARM 64 10 aarch64 Red Hat Enterprise Linux for ARM 64 - Extended Update Support 10.2 aarch64 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 10.2 aarch64 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 10.2 s390x Red Hat Enterprise Linux for Power, little endian - 4 years of support 10.2 ppc64le Red Hat Enterprise Linux for x86_64 - 4 years of updates 10.2 x86_64 Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 10.2 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 10.2 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 10.2 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 10.2 s390x Fixes BZ - 2476469 - CVE-2026-8388 firefox: thunderbird: Incorrect boundary conditions in the JavaScript Engine: JIT component BZ - 2476475 - CVE-2026-8391 firefox: thunderbird: Other issue in the JavaScript Engine component BZ - 2476492 - CVE-2026-8401 firefox: thunderbird: Sandbox escape in the Profile Backup component BZ - 2479839 - CVE-2026-8956 firefox: Integer overflow in the Networking: JAR component BZ - 2479840 - CVE-2026-8975 firefox: Memory safety bugs fixed in Firefox ESR 115.36, Firefox ESR 140.11 and Firefox 151 BZ - 2479842 - CVE-2026-8955 firefox: thunderbird: Privilege escalation in the DOM: Workers component BZ - 2479846 - CVE-2026-8968 firefox: Denial-of-service due to invalid pointer in the Audio/Video: Web Codecs component BZ - 2479847 - CVE-2026-8954 firefox: Incorrect boundary conditions, integer overflow in the Audio/Video component BZ - 2479848 - CVE-2026-8958 firefox: Information disclosure, sandbox escape in the Security: Process Sandboxing component BZ - 2479849 - CVE-2026-8946 firefox: thunderbird: Incorrect boundary conditions in the Audio/Video: Web Codecs component BZ - 2479852 - CVE-2026-8970 firefox: Privilege escalation in the Security component BZ - 2479853 - CVE-2026-8950 firefox: Same-origin policy bypass in the Networking: HTTP component BZ - 2479855 - CVE-2026-8974 firefox: Memory safety bugs fixed in Firefox ESR 140.11 and Firefox 151 BZ - 2479860 - CVE-2026-8953 firefox: Sandbox escape due to use-after-free in the Disability Access APIs component BZ - 2479861 - CVE-2026-8959 firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component BZ - 2479871 - CVE-2026-8961 firefox: Spoofing issue in the Form Autofill component BZ - 2479873 - CVE-2026-8947 firefox: thunderbird: Use-after-free in the DOM: Bindings (WebIDL) component BZ - 2479876 - CVE-2026-8962 firefox: Mitigation bypass in the DOM: Security component BZ - 2479880 - CVE-2026-8957 firefox: Privilege escalation in the Enterprise Policies component CVEs CVE-2026-8388 CVE-2026-8391 CVE-2026-8401 CVE-2026-8946 CVE-2026-8947 CVE-2026-8950 CVE-2026-8953 CVE-2026-8954 CVE-2026-8955 CVE-2026-8956 CVE-2026-8957 CVE-2026-8958 CVE-2026-8959 CVE-2026-8961 CVE-2026-8962 CVE-2026-8968 CVE-2026-8970 CVE-2026-8974 CVE-2026-8975 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-140.11.0-1.el10_2.src.rpm SHA-256: 456aed19355ccd92f1d34746c2d232ee84f312ad48d3c90b1f8a09e4ef169e34 x86_64 thunderbird-140.11.0-1.el10_2.x86_64.rpm SHA-256: 7527ca8c3c6b0b5a9b0984a572cf850f93833d93938d8380570c16315f0150ca thunderbird-debuginfo-140.11.0-1.el10_2.x86_64.rpm SHA-256: f42e0a4e5865ce16ae45b3ae6c419520a3e577f9a451ec0cc9fd04f0ec61a0d0 thunderbird-debugsource-140.11.0-1.el10_2.x86_64.rpm SHA-256: 4e16214471071d4506c3f05ca6b1a20e81f5beff9f48bedd3a369df2895ea501 Red Hat Enterprise Linux for x86_64 - Extended Update Support 10.2 SRPM thunderbird-140.11.0-1.el10_2.src.rpm SHA-256: 456aed19355ccd92f1d34746c2d232ee84f312ad48d3c90b1f8a09e4ef169e34 x86_64 thunderbird-140.11.0-1.el10_2.x86_64.rpm SHA-256: 7527ca8c3c6b0b5a9b0984a572cf850f93833d93938d8380570c16315f0150ca thunderbird-debuginfo-140.11.0-1.el10_2.x86_64.rpm SHA-256: f42e0a4e5865ce16ae45b3ae6c419520a3e577f9a451ec0cc9fd04f0ec61a0d0 thunderbird-debugsource-140.11.0-1.el10_2.x86_64.rpm SHA-256: 4e16214471071d4506c3f05ca6b1a20e81f5beff9f48bedd3a369df2895ea501 Red Hat Enterprise Linux for IBM z Systems 10 SRPM thunderbird-140.11.0-1.el10_2.src.rpm SHA-256: 456aed19355ccd92f1d34746c2d232ee84f312ad48d3c90b1f8a09e4ef169e34 s390x thunderbird-140.11.0-1.el10_2.s390x.rpm SHA-256: 166e11e68affba3759245da24fd6f89af34cc14fffaadb81f8724bad6fbddd2f thunderbird-debuginfo-140.11.0-1.el10_2.s390x.rpm SHA-256: a405f09b1a25b89fef5d3e3788dbceb227458fe3fd7801a91ff368a4fd5ae32f thunderbird-debugsource-140.11.0-1.el10_2.s390x.rpm SHA-256: 01cd8d58be815a778d407340c87c9caf5c58e5fa81f44c6316a1e770f6a2ce83 Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.2 SRPM thunderbird-140.11.0-1.el10_2.src.rpm SHA-256: 456aed19355ccd92f1d34746c2d232ee84f312ad48d3c90b1f8a09e4ef169e34 s390x thunderbird-140.11.0-1.el10_2.s390x.rpm SHA-256: 166e11e68affba3759245da24fd6f89af34cc14fffaadb81f8724bad6fbddd2f thunderbird-debuginfo-140.11.0-1.el10_2.s390x.rpm SHA-256: a405f09b1a25b89fef5d3e3788dbceb227458fe3fd7801a91ff368a4fd5ae32f thunderbird-debugsource-140.11.0-1.el10_2.s390x.rpm SHA-256: 01cd8d58be815a778d407340c87c9caf5c58e5fa81f44c6316a1e770f6a2ce83 Red Hat Enterprise Linux for Power, little endian 10 SRPM thunderbird-140.11.0-1.el10_2.src.rpm SHA-256: 456aed19355ccd92f1d34746c2d232ee84f312ad48d3c90b1f8a09e4ef169e34 ppc64le thunderbird-140.11.0-1.el10_2.ppc64le.rpm SHA-256: 4ce1e4c3b5607116ee06e13877fc3884b3a6c27c44c41fcb9b95f02db04afa1d thunderbird-debuginfo-140.11.0-1.el10_2.ppc64le.rpm SHA-256: 820d945027799ae65a8d9d0d5268d7e3de1fee3087dd79bfc5fdb0489b9639db thunderbird-debugsource-140.11.0-1.el10_2.ppc64le.rpm SHA-256: 48007c82cb4bb86feec846f025476fa6b69b9bf4fa74d18096dc1f7a2084da8d Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.2 SRPM thunderbird-140.11.0-1.el10_2.src.rpm SHA-256: 456aed19355ccd92f1d34746c2d232ee84f312ad48d3c90b1f8a09e4ef169e34 ppc64le thunderbird-140.11.0-1.el10_2.ppc64le.rpm SHA-256: 4ce1e4c3b5607116ee06e13877fc3884b3a6c27c44c41fcb9b95f02db04afa1d thunderbird-debuginfo-140.11.0-1.el10_2.ppc64le.rpm SHA-256: 820d945027799ae65a8d9d0d5268d7e3de1fee3087dd79bfc5fdb0489b9639db thunderbird-debugsource-140.11.0-1.el10_2.ppc64le.rpm SHA-256: 48007c82cb4bb86feec846f025476fa6b69b9bf4fa74d18096dc1f7a2084da8d Red Hat Enterprise Linux for ARM 64 10 SRPM thunderbird-140.11.0-1.el10_2.src.rpm SHA-256: 456aed19355ccd92f1d34746c2d232ee84f312ad48d3c90b1f8a09e4ef169e34 aarch64 thunderbird-140.11.0-1.el10_2.aarch64.rpm SHA-256: f6825bdb9a17e15dd3561ae4c96c7eae9