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OpenAdvisories
High ALSA-2026:21381 22 CVEs

Important: thunderbird security update

Published May 27, 2026 · Updated Nov 6, 2026

Ecosystem: AlmaLinux

Summary

Mozilla Thunderbird is a standalone mail and newsgroup client.

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: Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component (CVE-2026-8959)
* 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.

Fixed packages 1

ReleasePackageFixed in
AlmaLinux · 9 thunderbird 140.11.0-1.el9_8.alma.1

Vulnerabilities 22

References

  • report
    https://access.redhat.com/security/cve/CVE-2026-8388
  • report
    https://access.redhat.com/security/cve/CVE-2026-8391
  • report
    https://access.redhat.com/security/cve/CVE-2026-8401
  • report
    https://access.redhat.com/security/cve/CVE-2026-8946
  • report
    https://access.redhat.com/security/cve/CVE-2026-8947
  • report
    https://access.redhat.com/security/cve/CVE-2026-8950
  • report
    https://access.redhat.com/security/cve/CVE-2026-8953
  • report
    https://access.redhat.com/security/cve/CVE-2026-8954
  • report
    https://access.redhat.com/security/cve/CVE-2026-8955
  • report
    https://access.redhat.com/security/cve/CVE-2026-8956
  • report
    https://access.redhat.com/security/cve/CVE-2026-8957
  • report
    https://access.redhat.com/security/cve/CVE-2026-8958
  • report
    https://access.redhat.com/security/cve/CVE-2026-8959
  • report
    https://access.redhat.com/security/cve/CVE-2026-8961
  • report
    https://access.redhat.com/security/cve/CVE-2026-8962
  • report
    https://access.redhat.com/security/cve/CVE-2026-8968
  • report
    https://access.redhat.com/security/cve/CVE-2026-8970
  • report
    https://access.redhat.com/security/cve/CVE-2026-8974
  • report
    https://access.redhat.com/security/cve/CVE-2026-8975
  • report
    https://bugzilla.redhat.com/2476469
  • report
    https://bugzilla.redhat.com/2476475
  • report
    https://bugzilla.redhat.com/2476492
  • report
    https://bugzilla.redhat.com/2479839
  • report
    https://bugzilla.redhat.com/2479840
  • report
    https://bugzilla.redhat.com/2479842
  • report
    https://bugzilla.redhat.com/2479846
  • report
    https://bugzilla.redhat.com/2479847
  • report
    https://bugzilla.redhat.com/2479848
  • report
    https://bugzilla.redhat.com/2479849
  • report
    https://bugzilla.redhat.com/2479852
  • report
    https://bugzilla.redhat.com/2479853
  • report
    https://bugzilla.redhat.com/2479855
  • report
    https://bugzilla.redhat.com/2479860
  • report
    https://bugzilla.redhat.com/2479861
  • report
    https://bugzilla.redhat.com/2479871
  • report
    https://bugzilla.redhat.com/2479873
  • report
    https://bugzilla.redhat.com/2479876
  • report
    https://bugzilla.redhat.com/2479880
  • advisory
    https://errata.almalinux.org/9/ALSA-2026-21381.html