RHSA-2026:77627HighCVSS 7.5

Red Hat Security Advisory: thunderbird security update

Published
October 8, 2026
Last Modified
October 13, 2026

🔗 CVE IDs covered (13)

CVE-2026-75874 →CVE-2026-84119 →CVE-2026-84120 →CVE-2026-84124 →CVE-2026-84639 →CVE-2026-84641 →CVE-2026-16365 →CVE-2026-84121 →CVE-2026-84122 →CVE-2026-84131 →CVE-2026-84143 →CVE-2026-84145 →CVE-2026-84640 →

📋 Description

CVE-2026-16365 — firefox: thunderbird: Privilege escalation in the DOM: Workers component CVE-2026-75874 — firefox: thunderbird: Sandbox escape in the Remote Settings Client component CVE-2026-84119 — firefox: Sandbox escape due to use-after-free in the DOM: Navigation component CVE-2026-84120 — firefox: Use-after-free in the Audio/Video component CVE-2026-84121 — firefox: Sandbox escape due to use-after-free in the DOM: Security component CVE-2026-84122 — firefox: Use-after-free in the Audio/Video component CVE-2026-84124 — firefox: Use-after-free in the DOM: Core & HTML component CVE-2026-84131 — firefox: Privilege escalation due to invalid pointer in the Graphics component CVE-2026-84143 — firefox: Internally found bugs fixed in Firefox 155, Firefox ESR 153.2 and Firefox ESR 140.15 CVE-2026-84145 — firefox: Internally found bugs fixed in Firefox 155, Firefox ESR 153.2, Firefox ESR 140.15 and Firefox ESR 115.40 CVE-2026-84639 — thunderbird: Uninitialized memory in MIME parsing CVE-2026-84640 — thunderbird: One byte overflow read in mail parser CVE-2026-84641 — thunderbird: Information disclosure due to malicious IMAP server response

🎯 Affected products14

  • Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-0:140.15.0-1.el9_4.aarch64 as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-0:140.15.0-1.el9_4.ppc64le as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-0:140.15.0-1.el9_4.s390x as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-0:140.15.0-1.el9_4.src as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-0:140.15.0-1.el9_4.x86_64 as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-debuginfo-0:140.15.0-1.el9_4.aarch64 as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-debuginfo-0:140.15.0-1.el9_4.ppc64le as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-debuginfo-0:140.15.0-1.el9_4.s390x as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-debuginfo-0:140.15.0-1.el9_4.x86_64 as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-debugsource-0:140.15.0-1.el9_4.aarch64 as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-debugsource-0:140.15.0-1.el9_4.ppc64le as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-debugsource-0:140.15.0-1.el9_4.s390x as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • thunderbird-debugsource-0:140.15.0-1.el9_4.x86_64 as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

🔗 References (16)