Red Hat Product Errata RHSA-2026:26493 - Security Advisory Issued: 2026-06-17 Updated: 2026-06-17 RHSA-2026:26493 - 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 9.4 Update Services for SAP Solutions. 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 Server - AUS 9.4 x86_64 Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.4 ppc64le Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.4 x86_64 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.4 aarch64 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.4 s390x Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.4 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.4 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.4 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.4 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 Server - AUS 9.4 SRPM firefox-140.11.0-1.el9_4.src.rpm SHA-256: 4a6288ed9af3826704bccaefb1dffd7202b8d5e69d1ffded6bcfb0ad930aa23b x86_64 firefox-140.11.0-1.el9_4.x86_64.rpm SHA-256: feb2a01163727523f78c804968bb29659e4fdaf331e571b0772eed29626d9ae2 firefox-debuginfo-140.11.0-1.el9_4.x86_64.rpm SHA-256: 82d2b3d967f0a2da57018cca015c9e658e87e78bb4d8f852212a25ad63792634 firefox-debugsource-140.11.0-1.el9_4.x86_64.rpm SHA-256: fbd8c643088aa69984b12d8910693f13954daf3120da3dcf57fcc207d8fcc733 firefox-x11-140.11.0-1.el9_4.x86_64.rpm SHA-256: 49c0e57907af391ee510da5e218a61f1dacbaa6cc43c5bcdcfc6f401550f2057 Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.4 SRPM firefox-140.11.0-1.el9_4.src.rpm SHA-256: 4a6288ed9af3826704bccaefb1dffd7202b8d5e69d1ffded6bcfb0ad930aa23b ppc64le firefox-140.11.0-1.el9_4.ppc64le.rpm SHA-256: 3fcd353f8c0da2cc198c137d6c5eab0d672694ad2d3b57680ac42a125cc01c1e firefox-debuginfo-140.11.0-1.el9_4.ppc64le.rpm SHA-256: d6e2b89f9af54b8d1453723ae24490320e2fe09e1560f62dc3c80fc8683aca8f firefox-debugsource-140.11.0-1.el9_4.ppc64le.rpm SHA-256: 68fb0aac59add02f91864f2f616b4e39ff7743e5952b5b8c5604d5eadb3d3d9c firefox-x11-140.11.0-1.el9_4.ppc64le.rpm SHA-256: 5a0bc370e43b64d06fcf9debe5586198522429b0f06a5fcc12ebe7661fe5b3c6 Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.4 SRPM firefox-140.11.0-1.el9_4.src.rpm SHA-256: 4a6288ed9af3826704bccaefb1dffd7202b8d5e69d1ffded6bcfb0ad930aa23b x86_64 firefox-140.11.0-1.el9_4.x86_64.rpm SHA-256: feb2a01163727523f78c804968bb29659e4fdaf331e571b0772eed29626d9ae2 firefox-debuginfo-140.11.0-1.el9_4.x86_64.rpm SHA-256: 82d2b3d967f0a2da57018cca015c9e658e87e78bb4d8f852212a25ad63792634 firefox-debugsource-140.11.0-1.el9_4.x86_64.rpm SHA-256: fbd8c643088aa69984b12d8910693f13954daf3120da3dcf57fcc207d8fcc733 firefox-x11-140.11.0-1.el9_4.x86_64.rpm SHA-256: 49c0e57907af391ee510da5e218a61f1dacbaa6cc43c5bcdcfc6f401550f2057 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.4 SRPM firefox-140.11.0-1.el9_4.src.rpm SHA-256: 4a6288ed9af3826704bccaefb1dffd7202b8d5e69d1ffded6bcfb0ad930aa23b aarch64 firefox-140.11.0-1.el9_4.aarch64.rpm SHA-256: ae6843f0e678a32df39dc6073613bb2abaae3b9e17a883dd3557761b3d0cb8e2 firefox-debuginfo-140.11.0-1.el9_4.aarch64.rpm SHA-256: 07635ba30f8434796bc8c49a71132b79f9372ad0a416a2ecd0d07f98601ef671 firefox-debugsource-140.11.0-1.el9_4.aarch64.rpm SHA-256: b28e69e31bcc01f21778c04a1ad8a2614832c41b78decb236a80b4a74c38f0b1 firefox-x11-140.11.0-1.el9_4.aarch64.rpm SHA-256: 0050ab23a87344be71faf6dc2c15774b4c03f7fc19b75472b32a88ec7e5c31cf Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.4 SRPM firefox-140.11.0-1.el9_4.src.rpm SHA-256: 4a6288ed9af3826704bccaefb1dffd7202b8d5e69d1ffded6bcfb0ad930aa23b s390x firefox-140.11.0-1.el9_4.s390x.rpm SHA-256: 5c99da792db08bd847c9d986ffcf93e28a7af581250c624912b8a56632f38848 firefox-debuginfo-140.11.0-1.el9_4.s390x.rpm SHA-256: 35dc9e51619c28b373626aa17cf54362b9c75c22a025ce239ac8e734c54b09f0 firefox-debugsource-140.11.0-1.el9_4.s390x.rpm SHA-256: 9ed6ec4933c1c00e4e03093263179159bae20a1a60cd79406ef6c5447d9ae742 firefox-x11-140.11.0-1.el9_4.s390x.rpm SHA-256: 6d72507ca5fc00c2c35ebc2219f499bc43ca13909e57499762a9d97037ede969 Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.4 SRPM firefox-140.11.0-1.el9_4.src.rpm SHA-256: 4a6288ed9af3826704bccaefb1dffd7202b8d5e69d1ffded6bcfb0ad930aa23b x86_64 firefox-140.11.0-1.el9_4.x86_64.rpm SHA-256: feb2a01163727523f78c804968bb29659e4fdaf331e571b0772eed29626d9ae2 firefox-debuginfo-140.11.0-1.el9_4.x86_64.rpm SHA-256: 82d2b3d967f0a2da57018cca015c9e658e87e78bb4d8f852212a25ad63792634 firefox-debugsource-140.11.0-1.el9_4.x86_64.rpm SHA-256: fbd8c643088aa69984b12d8910693f13954daf3120da3dcf57fcc207d8fcc733 firefox-x11-140.11.0-1.el9_4.x86_64.rpm SHA-256: 49c0e57907af391ee510da5e218a61f1dacbaa6cc43c5bcdcfc6f401550f2057 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.4 SRPM firefox-140.11.0-1.el9_4.src.rpm SHA-256: 4a6288ed9af3826704bccaefb1dffd7202b8d5e69d1ffded6bcfb0ad930aa23b aarch64 firefox-140.11.0-1.el9_4.aarch64.rpm SHA-256: ae6843f0e678a32df39dc6073613bb2abaae3b9e17a883dd3557761