RHSA-2026:20586 - Security Advisory

Topic

An update for thunderbird is now available for Red Hat Enterprise Linux 8.

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 Thunderbird is a standalone mail and newsgroup client.

Security Fix(es):

• firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.10.1 and Firefox 150.0.1 (CVE-2026-7323)
• firefox: thunderbird: Information disclosure due to incorrect boundary conditions in the Audio/Video component (CVE-2026-7320)
• firefox: thunderbird: Memory safety bugs fixed in Thunderbird ESR 140.10.1 and Thunderbird 150.0.1 (CVE-2026-7322)
• firefox: thunderbird: webrtc: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component (CVE-2026-7321)

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 for x86_64 8 x86_64
• Red Hat Enterprise Linux for IBM z Systems 8 s390x
• Red Hat Enterprise Linux for Power, little endian 8 ppc64le
• Red Hat Enterprise Linux for ARM 64 8 aarch64
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 8.10 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 8.10 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 8.10 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 8.10 s390x

Fixes

• BZ - 2463481 - CVE-2026-7323 firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.10.1 and Firefox 150.0.1
• BZ - 2463483 - CVE-2026-7320 firefox: thunderbird: Information disclosure due to incorrect boundary conditions in the Audio/Video component
• BZ - 2463484 - CVE-2026-7322 firefox: thunderbird: Memory safety bugs fixed in Thunderbird ESR 140.10.1 and Thunderbird 150.0.1
• BZ - 2463485 - CVE-2026-7321 firefox: thunderbird: webrtc: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component

CVEs

• CVE-2026-7320
• CVE-2026-7321
• CVE-2026-7322
• CVE-2026-7323

References

• https://access.redhat.com/security/updates/classification/#important