An update for thunderbird is now available for Red Hat Enterprise Linux 8.6
 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions, and Red Hat Enterprise Linux 8.6 Telecommunications Update Service.

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.

Mozilla Thunderbird is a standalone mail and newsgroup client.

Security Fix(es):

* firefox: thunderbird: Out-of-bounds access when resolving Promise objects
 (CVE-2025-4918)

* firefox: thunderbird: Out-of-bounds access when optimizing linear sums
 (CVE-2025-4919)

* firefox: thunderbird: Clickjacking vulnerability could have led to leaking
 saved payment card details (CVE-2025-5267)

* firefox: thunderbird: Potential local code execution in ?Copy as cURL?
 command (CVE-2025-5264)

* firefox: thunderbird: Memory safety bugs (CVE-2025-5268)

* firefox: thunderbird: Script element events leaked cross-origin resource
 status (CVE-2025-5266)

* firefox: thunderbird: Error handling for script execution was incorrectly
 isolated from web content (CVE-2025-5263)

* firefox: thunderbird: Memory safety bug (CVE-2025-5269)

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.

This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.

CVE-2025-4918: Out-of-bounds Write (CWE-787)
CVE-2025-4919: Out-of-bounds Write (CWE-787)
CVE-2025-5263: Inclusion of Functionality from Untrusted Control Sphere
 (CWE-829)
CVE-2025-5264: Improper Encoding or Escaping of Output (CWE-116)
CVE-2025-5266: Inclusion of Functionality from Untrusted Control Sphere
 (CWE-829)
CVE-2025-5267: Improper Restriction of Rendered UI Layers or Frames (CWE-1021)
CVE-2025-5268: Improper Restriction of Operations within the Bounds of a Memory
 Buffer (CWE-119)
CVE-2025-5269: Improper Restriction of Operations within the Bounds of a Memory
 Buffer (CWE-119)