Mozilla has released security updates to address security vulnerabilities in Firefox, Firefox ESR, and Thunderbird. An attacker could exploit some of these vulnerabilities to trigger cross-site scripting, remote code execution, security restriction bypass, sensitive information disclosure, spoofing and denial of service condition on the targeted system. Security vulnerabilities fixed in Firefox 140, Firefox ESR 115.25, Firefox ESR 128.12, Thunderbird 128.12 and Thunderbird 140. More information on vulnerabilities and updates is available in Mozilla security advisories:

• MFSA 2025-54