RHSA-2025:17367 — Security Advisory

An update for firefox 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 Firefox is an open-source web browser, designed for standards compliance, performance, and portability.

Security Fix(es):

• firefox: thunderbird: Sandbox escape due to use-after-free in the Graphics: Canvas2D component (CVE-2025-10527)

• firefox: thunderbird: Incorrect boundary conditions in the JavaScript: GC component (CVE-2025-10532)

• firefox: thunderbird: Sandbox escape due to undefined behavior, invalid pointer in the Graphics: Canvas2D component (CVE-2025-10528)

• firefox: thunderbird: Same-origin policy bypass in the Layout component (CVE-2025-10529)

• firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.3, Thunderbird ESR 140.3, Firefox 143 and Thunderbird 143 (CVE-2025-10537)

• firefox: thunderbird: Information disclosure in the Networking: Cache component (CVE-2025-10536)

• firefox: thunderbird: Integer overflow in the SVG component (CVE-2025-10533)

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.