This advisory covers a set of nine security vulnerabilities in Mozilla Firefox and Thunderbird as packaged for Red Hat Enterprise Linux 7 Extended Lifecycle Support. The issues include a large branch table leading to truncated instructions (CVE-2025-8028), multiple memory safety bugs (CVE-2025-8034, CVE-2025-8035), incorrect URL stripping in CSP reports (CVE-2025-8031), partial return value writes in the JavaScript engine stack (CVE-2025-8027), potential user-assisted code execution via the 'Copy as cURL' command (CVE-2025-8030), incorrect JavaScript state machine behavior for generators (CVE-2025-8033), CSP bypass via XSLT documents (CVE-2025-8032), and execution of javascript: URLs on object and embed tags (CVE-2025-8029). Red Hat has issued updated Firefox packages to address these vulnerabilities.

The vulnerabilities collectively pose risks including memory safety issues that could lead to crashes or code execution, incorrect enforcement of Content Security Policy potentially allowing malicious content, and user-assisted code execution vectors. These issues could impact the confidentiality, integrity, and availability of systems running affected Firefox or Thunderbird versions on Red Hat Enterprise Linux 7 Extended Lifecycle Support. The severity is rated as Important by Red Hat.

Red Hat has released updated Firefox packages for Red Hat Enterprise Linux 7 Extended Lifecycle Support that address these vulnerabilities. Users should apply the security update as detailed in Red Hat advisory RHSA-2025:12278 and the referenced article https://access.redhat.com/articles/11258. No additional mitigation steps are indicated beyond applying the official patches.