Red Hat Product Errata RHSA-2026:26492 - Security Advisory Issued: 2026-06-17 Updated: 2026-06-17 RHSA-2026:26492 - 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 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 Firefox is an open-source web browser, designed for standards compliance, performance, and portability. 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: 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 - 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 - 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 - 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-2026-8961 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 - Extended Update Support 9.6 SRPM firefox-140.11.0-1.el9_6.src.rpm SHA-256: 6b122972a2b33bda5e995f9d684cf2ec8c333656048503fb89ed96cd875a5735 x86_64 firefox-140.11.0-1.el9_6.x86_64.rpm SHA-256: 36dd5da96fc18fe09f4bef8538af01bb5eea7b12977adb5359e89fc8de1cac94 firefox-debuginfo-140.11.0-1.el9_6.x86_64.rpm SHA-256: 614a26ca3ce51b749cb8f1c22fca9e805471dd1811585eb506e5e33fd7c3a099 firefox-debugsource-140.11.0-1.el9_6.x86_64.rpm SHA-256: b5f82ae619eaccf2f9658b293d225dc26991279bc7f75fb46b6a2198e865235e firefox-x11-140.11.0-1.el9_6.x86_64.rpm SHA-256: 10f96eb7afe65426cfebf53a8e6b3f696b306abae11367b8afdfe623ebd5af59 Red Hat Enterprise Linux Server - AUS 9.6 SRPM firefox-140.11.0-1.el9_6.src.rpm SHA-256: 6b122972a2b33bda5e995f9d684cf2ec8c333656048503fb89ed96cd875a5735 x86_64 firefox-140.11.0-1.el9_6.x86_64.rpm SHA-256: 36dd5da96fc18fe09f4bef8538af01bb5eea7b12977adb5359e89fc8de1cac94 firefox-debuginfo-140.11.0-1.el9_6.x86_64.rpm SHA-256: 614a26ca3ce51b749cb8f1c22fca9e805471dd1811585eb506e5e33fd7c3a099 firefox-debugsource-140.11.0-1.el9_6.x86_64.rpm SHA-256: b5f82ae619eaccf2f9658b293d225dc26991279bc7f75fb46b6a2198e865235e firefox-x11-140.11.0-1.el9_6.x86_64.rpm SHA-256: 10f96eb7afe65426cfebf53a8e6b3f696b306abae11367b8afdfe623ebd5af59 Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.6 SRPM firefox-140.11.0-1.el9_6.src.rpm SHA-256: 6b122972a2b33bda5e995f9d684cf2ec8c333656048503fb89ed96cd875a5735 s390x firefox-140.11.0-1.el9_6.s390x.rpm SHA-256: 4e28d2a22835dfe302161b4d75d2f9983faee488db87d8cf57f5c9404e8e5ba1 firefox-debuginfo-140.11.0-1.el9_6.s390x.rpm SHA-256: 8b0a6961cef8d74b651e8b15279320684cfa69e66e1498939e0ef398521619fc firefox-debugsource-140.11.0-1.el9_6.s390x.rpm SHA-256: 040ae32716da4220225821cefe592928ae71c282e44617a2d388d38b29978e4f firefox-x11-140.11.0-1.el9_6.s390x.rpm SHA-256: 7af8f319ce149aa3eef680b18a5400706fb32223256caba70779f36ee90c7fcc Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.6 SRPM firefox-140.11.0-1.el9_6.src.rpm SHA-256: 6b122972a2b33bda5e995f9d684cf2ec8c333656048503fb89ed96cd875a5735 ppc64le firefox-140.11.0-1.el9_6.ppc64le.rpm SHA-256: 4878b7b66fb0bda4f88e43da39d56b80636291f083d8e00299a8077800b92059 firefox-debuginfo-140.11.0-1.el9_6.ppc64le.rpm SHA-256: 81f54317aa0643384e1bb0146d2b125c663dd7b79bf2a01674287b0521fb1eb1 firefox-debugsource-140.11.0-1.el9_6.ppc64le.rpm SHA-256: f1bad448c001be215aaf5eefb31de683e625a438199621cc41018d150380052e firefox-x11-140.11.0-1.el9_6.ppc64le.rpm SHA-256: 1136dfc569ecc08a6f9c3a519704c45f8c36a47c30c770b418f0ed92ff0d5291 Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.6 SRPM firefox-140.11.0-1.el9_6.src.rpm SHA-256: 6b122972a2b33bda5e995f9d684cf2ec8c333656048503fb89ed96cd875a5735 aarch64 firefox-140.11.0-1.el9_6.aarch64.rpm SHA-256: 47816121a0c879f494f6dcb28fb5214c9fbc94f76d41884d3f805343d8b4ef77 firefox-debuginfo-140.11.0-1.el9_6.aarch64.rpm SHA-256: 087194209b9f6d890c009560d157c9c6062d16991837f9b24b418df87ccc8974 firefox-debugsource-140.11.0-1.el9_6.aarch64.rpm SHA-256: 7596143c32e11f2fe6a1c83312927c307a2531130569a0fb27ee5baa57e503b2 firefox-x11-140.11.0-1.el9_6.aarch64.rpm SHA-256: 967c97884d0eea1e1f6f56fbe674d8d5a5673a61231a64fbe1d91bbf8c6e5e8f Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.6 SRPM firefox-140.11.0-1.el9_6.src.rpm SHA-256: 6b122972a2b33bda5e995f9d684cf2ec8c333656048503fb89ed96cd875a5735 ppc64le firefox-140.11.0-1.el9_6.ppc64le.rpm SHA-256: 4878b7b66fb0bda4f88e43da39d56b80636291f083d8e00299a8077800b92059 firefox-debuginfo-140.11.0-1.el9_6.ppc64le.rpm SHA-256: 81f54317aa0643384e1bb0146d2b125c663dd7b79bf2a01674287b0521fb1eb1 firefox-debugsource-140.11.0-1.el9_6.ppc64le.rpm SHA-256: f1bad448c001be215aaf5eefb31de683e625a438199621cc41018d150380052e firefox-x11-140.11.0-1.el9_6.ppc64le.rpm SHA-256: 1136dfc569ecc08a6f9c3