Javier Marcos

**Name of the Vulnerable Software and Affected Versions** Firefox versions prior to 74.0.1 Firefox ESR versions prior to 68.6.1 Thunderbird versions prior to 68.7.0 **Description** The issue is related to a use-after-free flaw in the nsDocShell destructor, which can be triggered under certain conditions. This can lead to a race condition, causing the use-after-free. There have been targeted attacks in the wild exploiting this flaw. The exploitation of this issue may allow a remote attacker to access confidential data, compromise data integrity, and cause a denial of service. **Recommendations** For Firefox versions prior to 74.0.1, update to version 74.0.1 or later. For Firefox ESR versions prior to 68.6.1, update to version 68.6.1 or later. For Thunderbird versions prior to 68.7.0, update to version 68.7.0 or later.

**Name of the Vulnerable Software and Affected Versions** Firefox versions prior to 74.0.1 Firefox ESR versions prior to 68.6.1 Thunderbird versions prior to 68.7.0 **Description** The issue is related to a use-after-free condition in the ReadableStream component, potentially allowing a remote attacker to access confidential data, compromise its integrity, and cause a denial of service. There have been targeted attacks in the wild exploiting this flaw. **Recommendations** For Firefox versions prior to 74.0.1, update to version 74.0.1 or later. For Firefox ESR versions prior to 68.6.1, update to version 68.6.1 or later. For Thunderbird versions prior to 68.7.0, update to version 68.7.0 or later.