CVE-2021-43535

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 93 Thunderbird versions prior to 91.3 Firefox ESR versions prior to 91.3

Description A use-after-free issue could have occurred when an HTTP2 session object was released on a different thread, leading to memory corruption and a potentially exploitable crash. The issue is related to the use of memory after it has been freed, which may allow a remote attacker to execute arbitrary code.

Recommendations For Firefox versions prior to 93, update to version 93 or later to resolve the issue. For Thunderbird versions prior to 91.3, update to version 91.3 or later to resolve the issue. For Firefox ESR versions prior to 91.3, update to version 91.3 or later to resolve the issue.