Mozilla · Firefox Esr · CVE-2021-43536
**Name of the Vulnerable Software and Affected Versions**
Thunderbird versions prior to 91.4.0
Firefox ESR versions prior to 91.4.0
Firefox versions prior to 95
**Description**
The issue is related to the exposure of information under certain circumstances, potentially allowing a remote attacker to access confidential information using a specially crafted web page. Asynchronous functions could cause navigation to fail while exposing the target URL.
**Recommendations**
For Thunderbird versions prior to 91.4.0, update to version 91.4.0 or later.
For Firefox ESR versions prior to 91.4.0, update to version 91.4.0 or later.
For Firefox versions prior to 95, update to version 95 or later.