RHSA-2026:14303HighCVSS 8.8

Red Hat Security Advisory: thunderbird security update

Published
May 6, 2026
Last Modified
October 12, 2026

🔗 CVE IDs covered (5)

CVE-2026-5734 →CVE-2026-33416 →CVE-2026-33636 →CVE-2026-5731 →CVE-2026-5732 →

📋 Description

CVE-2026-5731 — thunderbird: firefox: Memory safety bugs fixed in Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2 CVE-2026-5732 — firefox: thunderbird: Incorrect boundary conditions, integer overflow in the Graphics: Text component CVE-2026-5734 — thunderbird: firefox: Memory safety bugs fixed in Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2 CVE-2026-33416 — libpng: libpng: Arbitrary code execution due to use-after-free vulnerability CVE-2026-33636 — libpng: libpng: Information disclosure and denial of service via out-of-bounds read/write in Neon palette expansion

🎯 Affected products10

  • Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • thunderbird-0:140.9.1-1.el8_4.src as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • thunderbird-0:140.9.1-1.el8_4.src as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • thunderbird-0:140.9.1-1.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • thunderbird-0:140.9.1-1.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • thunderbird-debuginfo-0:140.9.1-1.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • thunderbird-debuginfo-0:140.9.1-1.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • thunderbird-debugsource-0:140.9.1-1.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • thunderbird-debugsource-0:140.9.1-1.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)

✅ 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 Workaround: To reduce exposure, avoid processing untrusted PNG image files with applications that utilize libpng. Restricting the source of PNG images to trusted origins can limit the attack surface. Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

🔗 References (8)