RHSA-2025:4756 - Security Advisory

Topic

An update for firefox is now available for Red Hat Enterprise Linux 9.4 Extended Update Support.

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 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.

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 - Extended Update Support 9.4 x86_64
• Red Hat Enterprise Linux Server - AUS 9.4 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.4 s390x
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.4 ppc64le
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.4 aarch64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.4 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.4 x86_64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.4 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.4 s390x

Fixes

• BZ - 2362902 - CVE-2025-2817 firefox: thunderbird: Privilege escalation in Firefox Updater
• BZ - 2362904 - CVE-2025-4087 firefox: thunderbird: Unsafe attribute access during XPath parsing
• BZ - 2362907 - CVE-2025-4083 firefox: thunderbird: Process isolation bypass using "javascript:" URI links in cross-origin frames
• BZ - 2362912 - CVE-2025-4091 firefox: thunderbird: Memory safety bugs fixed in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10
• BZ - 2362915 - CVE-2025-4093 firefox: thunderbird: Memory safety bug fixed in Firefox ESR 128.10 and Thunderbird 128.10

CVEs

• CVE-2025-2817
• CVE-2025-4083
• CVE-2025-4087
• CVE-2025-4091
• CVE-2025-4093

References

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