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 elevation of privilege, arbitrary code execution, security restriction bypass, sensitive information disclosure, spoofing and denial of service condition on the targeted system. Security vulnerabilities fixed in Firefox 157, Firefox ESR 115.42, Firefox ESR 140.17, Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4.

More information on vulnerabilities and updates is available in Mozilla security advisories:

• MFSA 2026-103

• MFSA 2026-102

• MFSA 2026-101

• MFSA 2026-100

• MFSA 2026-99

• MFSA 2026-98

• MFSA 2026-97

Source: mozilla.org