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OpenAdvisories
High ALSA-2025:0147 2 CVEs

Important: thunderbird security update

Published Jan 9, 2025 · Updated Oct 29, 2026

Summary

Mozilla Thunderbird is a standalone mail and newsgroup client.

Security Fix(es):

* firefox: thunderbird: Memory safety bugs fixed in Firefox 134, Thunderbird 134, Firefox ESR 128.6, and Thunderbird 128.6 (CVE-2025-0243)
* firefox: thunderbird: Memory safety bugs fixed in Firefox 134, Thunderbird 134, Firefox ESR 115.19, Firefox ESR 128.6, Thunderbird 115.19, and Thunderbird 128.6 (CVE-2025-0242)

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 128.6.0-3.el9_5.alma.1

Vulnerabilities 2

  • Medium 6.5
    CVE-2025-0242 EPSS 15%

    Memory safety bugs fixed in Firefox 134, Thunderbird 134, Firefox ESR 115.19, Firefox ESR 128.6, Thunderbird 115.19, and Thunderbird 128.6

    Memory safety bugs present in Firefox 133, Thunderbird 133, Firefox ESR 115.18, Firefox ESR 128.5, Thunderbird 115.18, and Thunderbird 128.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could ha…

  • Medium 5.1

    Memory safety bugs fixed in Firefox 134, Thunderbird 134, Firefox ESR 128.6, and Thunderbird 128.6

    Memory safety bugs present in Firefox 133, Thunderbird 133, Firefox ESR 128.5, and Thunderbird 128.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.…

References

  • report
    https://access.redhat.com/security/cve/CVE-2025-0242
  • report
    https://access.redhat.com/security/cve/CVE-2025-0243
  • report
    https://bugzilla.redhat.com/2336175
  • report
    https://bugzilla.redhat.com/2336181
  • advisory
    https://errata.almalinux.org/9/ALSA-2025-0147.html