RHSA-2025:7544 — 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: Privilege escalation in Firefox Updater (CVE-2025-2817)

• firefox: thunderbird: Unsafe attribute access during XPath parsing (CVE-2025-4087)

• firefox: thunderbird: Process isolation bypass using "javascript:" URI links in cross-origin frames (CVE-2025-4083)

• firefox: thunderbird: Memory safety bugs fixed in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10 (CVE-2025-4091)

• firefox: thunderbird: Memory safety bug fixed in Firefox ESR 128.10 and Thunderbird 128.10 (CVE-2025-4093)

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.