CVE-2026-12304

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 152 Firefox ESR versions prior to 140.12 Thunderbird versions prior to 152 Thunderbird versions prior to 140.12

Description A same-origin policy bypass exists in the Networking: Cookies component. The same-origin policy is a critical security mechanism that restricts how a document or script loaded from one origin can interact with a resource from another origin.

Recommendations Update Firefox to version 152. Update Firefox ESR to version 140.12. Update Thunderbird to version 152. Update Thunderbird to version 140.12.