Yoav Weiss

**Name of the Vulnerable Software and Affected Versions** Firefox versions prior to 69 Thunderbird versions prior to 68.1 Thunderbird versions prior to 60.9 Firefox ESR versions prior to 60.9 Firefox ESR versions prior to 68.1 **Description** The issue is related to navigation events not fully adhering to the W3C's "Navigation-Timing Level 2" draft specification, specifically for the unload event. This resulted in potential cross-origin information exposure of history through timing side-channel attacks. The vulnerability may allow a remote attacker to access confidential data. **Recommendations** For Firefox versions prior to 69, update to version 69 or later. For Thunderbird versions prior to 68.1, update to version 68.1 or later. For Thunderbird versions prior to 60.9, update to version 60.9 or later. For Firefox ESR versions prior to 60.9, update to version 60.9 or later. For Firefox ESR versions prior to 68.1, update to version 68.1 or later.