Red Hat Product Errata RHSA-2026:65442 - Security Advisory Issued: 2026-09-08 Updated: 2026-09-08 RHSA-2026:65442 - Security Advisory Overview Updated Packages Synopsis Important: firefox 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 firefox is now available for Red Hat Enterprise Linux 7 Extended Lifecycle 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 Firefox is an open-source web browser, designed for standards compliance, performance, and portability. Security Fix(es): firefox: thunderbird: Mitigation bypass in the Data Loss Prevention component (CVE-2026-74983) firefox: thunderbird: Site isolation issue in the Graphics: CanvasWebGL component (CVE-2026-74934) firefox: thunderbird: Privilege escalation in the Networking: Cookies component (CVE-2026-74953) firefox: thunderbird: Internally found bugs fixed in Firefox ESR 140.14, Firefox ESR 153.1 and Firefox 154 (CVE-2026-74987) firefox: thunderbird: Information disclosure in the Graphics component (CVE-2026-74948) firefox: thunderbird: Use-after-free in the Graphics: ImageLib component (CVE-2026-74943) firefox: thunderbird: Information disclosure in the DOM: UI Events & Focus Handling component (CVE-2026-74971) firefox: thunderbird: Privilege escalation in the Graphics: CanvasWebGL component (CVE-2026-74941) firefox: Privilege escalation in the Shell Integration component (CVE-2026-74965) firefox: thunderbird: Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component (CVE-2026-74946) firefox: Race condition, use-after-free in the Graphics component (CVE-2026-74973) firefox: thunderbird: Privilege escalation due to use-after-free in the Graphics: Canvas2D component (CVE-2026-74949) firefox: thunderbird: Internally found bugs fixed in Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1 and Firefox 154 (CVE-2026-74990) firefox: thunderbird: Use-after-free in the JavaScript: WebAssembly component (CVE-2026-74936) firefox: thunderbird: Use-after-free in the Graphics: Text component (CVE-2026-74940) firefox: thunderbird: Site isolation issue in the WebExtensions component (CVE-2026-74960) firefox: thunderbird: Use-after-free in the Layout: Text and Fonts component (CVE-2026-74969) firefox: thunderbird: Mitigation bypass in the Storage: Cache API component (CVE-2026-74959) firefox: thunderbird: JIT miscompilation in the JavaScript Engine: JIT component (CVE-2026-74976) firefox: thunderbird: Same-origin policy bypass in the Graphics: ImageLib component (CVE-2026-74974) firefox: thunderbird: Mitigation bypass in the Safe Browsing component (CVE-2026-74957) firefox: thunderbird: Same-origin policy bypass in the Audio/Video: Playback component (CVE-2026-74967) firefox: Privilege escalation in the Remote Settings Client component (CVE-2026-74942) firefox: thunderbird: Privilege escalation in the DOM: Navigation component (CVE-2026-74939) firefox: thunderbird: Information disclosure in the DOM: Push Subscriptions component (CVE-2026-74972) firefox: thunderbird: Information disclosure in the Graphics: Text component (CVE-2026-74945) firefox: thunderbird: Same-origin policy bypass in the Networking: Cookies component (CVE-2026-74963) firefox: thunderbird: Use-after-free in the DOM: Core & HTML component (CVE-2026-74944) firefox: Integer overflow in the Graphics component (CVE-2026-74964) firefox: Site isolation issue in the Networking: Cookies component (CVE-2026-74962) firefox: thunderbird: Privilege escalation in the DOM: Networking component (CVE-2026-74935) 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 Server - Extended Life Cycle Support 7 x86_64 Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64 Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian 7 ppc64le Fixes BZ - 2517819 - CVE-2026-74983 firefox: thunderbird: Mitigation bypass in the Data Loss Prevention component BZ - 2517820 - CVE-2026-74934 firefox: thunderbird: Site isolation issue in the Graphics: CanvasWebGL component BZ - 2517822 - CVE-2026-74953 firefox: thunderbird: Privilege escalation in the Networking: Cookies component BZ - 2517823 - CVE-2026-74987 firefox: thunderbird: Internally found bugs fixed in Firefox ESR 140.14, Firefox ESR 153.1 and Firefox 154 BZ - 2517825 - CVE-2026-74948 firefox: thunderbird: Information disclosure in the Graphics component BZ - 2517826 - CVE-2026-74943 firefox: thunderbird: Use-after-free in the Graphics: ImageLib component BZ - 2517831 - CVE-2026-74971 firefox: thunderbird: Information disclosure in the DOM: UI Events & Focus Handling component BZ - 2517833 - CVE-2026-74941 firefox: thunderbird: Privilege escalation in the Graphics: CanvasWebGL component BZ - 2517834 - CVE-2026-74965 firefox: Privilege escalation in the Shell Integration component BZ - 2517835 - CVE-2026-74946 firefox: thunderbird: Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component BZ - 2517836 - CVE-2026-74973 firefox: Race condition, use-after-free in the Graphics component BZ - 2517837 - CVE-2026-74949 firefox: thunderbird: Privilege escalation due to use-after-free in the Graphics: Canvas2D component BZ - 2517839 - CVE-2026-74990 firefox: thunderbird: Internally found bugs fixed in Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1 and Firefox 154 BZ - 2517840 - CVE-2026-74936 firefox: thunderbird: Use-after-free in the JavaScript: WebAssembly component BZ - 2517841 - CVE-2026-74940 firefox: thunderbird: Use-after-free in the Graphics: Text component BZ - 2517845 - CVE-2026-74960 firefox: thunderbird: Site isolation issue in the WebExtensions component BZ - 2517846 - CVE-2026-74969 firefox: thunderbird: Use-after-free in the Layout: Text and Fonts component BZ - 2517849 - CVE-2026-74959 firefox: thunderbird: Mitigation bypass in the Storage: Cache API component BZ - 2517851 - CVE-2026-74976 firefox: thunderbird: JIT miscompilation in the JavaScript Engine: JIT component BZ - 2517853 - CVE-2026-74974 firefox: thunderbird: Same-origin policy bypass in the Graphics: ImageLib component BZ - 2517856 - CVE-2026-74957 firefox: thunderbird: Mitigation bypass in the Safe Browsing component BZ - 2517858 - CVE-2026-74967 firefox: thunderbird: Same-origin policy bypass in the Audio/Video: Playback component BZ - 2517859 - CVE-2026-74942 firefox: Privilege escalation in the Remote Settings Client component BZ - 2517860 - CVE-2026-74939 firefox: thunderbird: Privilege escalation in the DOM: Navigation component BZ - 2517862 - CVE-2026-74972 firefox: thunderbird: Information disclosure in the DOM: Push Subscriptions component BZ - 2517863 - CVE-2026-74945 firefox: thunderbird: Information disclosure in the Graphics: Text component BZ - 2517866 - CVE-2026-74963 firefox: thunderbird: Same-origin policy bypass in the Networking: Cookies component BZ - 2517868 - CVE-2026-74944 firefox: thunderbird: Use-after-free in the DOM: Core & HTML component BZ - 2517870 - CVE-2026-74964 firefox: Integer overflow in the Graphics component BZ - 2517872 - CVE-2026-74962 firefox: Site isolation issue in the Networking: Cookies component BZ - 2517874 - CVE-2026-74935 firefox: thunderbird: Privilege escalation in the DOM: Networking component CVEs CVE-2026-74934 CVE-2026-74935 CVE-2026-74936 CVE-2026-74939 CVE-2026-74940 CVE-2026-74941 CVE-2026-74942 CVE-2026-74943 CVE-2026-74944 CVE-2026-74945 CVE-2026-74946 CVE-2026-74948 CVE-2026-74949 CVE-2026-74953 CVE-2026-74957 CVE-2026-74959 CVE-2026-74960 CVE-2026-74962 CVE-2026-74963 CVE-2026-74964 CVE-2026-74965 CVE-2026-74967 CVE-2026-74969 CVE-2026-74971 CVE-2026-74972 CVE-2026-74973 CVE-2026-74974 CVE-2026-74976 CVE-2026-74983 CVE-2026-74987 CVE-2026-74990 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 Server - Extended Life Cycle Support 7 SRPM firefox-140.14.0-1.el7_9.src.rpm SHA-256: 6851849d060e1e7b63f70928582bbcd5675b50bb4727bab8eaf7f0d8940dd88f x86_64 firefox-140.14.0-1.el7_9.x86_64.rpm SHA-256: 48f56e387c9aafc0265c28724801bb2445949c8c712015d0147f1226d595cb41 Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 SRPM firefox-140.14.0-1.el7_9.src.rpm SHA-256: 6851849d060e1e7b63f70928582bbcd5675b50bb4727bab8eaf7f0d8940dd88f s390x firefox-140.14.0-1.el7_9.s390x.rpm SHA-256: 830fcc9e18db325e09ca1141cafaf8d54070ab5663af96be1f96eba0b573180c firefox-debuginfo-140.14.0-1.el7_9.s390x.rpm SHA-256: 417cd845f026a3d3067739b8d6f42e1e0e2373cc9d9b0e7a7472e732c8e7cc84 Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 SRPM firefox-140.14.0-1.el7_9.src.rpm SHA-256: 6851849d060e1e7b63f70928582bbcd5675b50bb4727bab8eaf7f0d8940dd88f ppc64 firefox-140.14.0-1.el7_9.ppc64.rpm SHA-256: 847d10785897ac970daaec65c968a9337577324f5bbe2b21bac39cede846c049 firefox-debuginfo-140.14.0-1.el7_9.ppc64.rpm SHA-256: 79d1a7af54f3b758dfa49f4274ca0c83340c9146bd2ca8b63e4101fabaab3b64 Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian 7 SRPM firefox-140.14.0-1.el7_9.s