Mozilla · Firefox · CVE-2020-26959
**Name of the Vulnerable Software and Affected Versions**
Firefox versions prior to 83
Firefox ESR versions prior to 78.5
Thunderbird versions prior to 78.5
**Description**
The issue is related to a use-after-free error in the WebRequestService component, which can lead to memory corruption and a potentially exploitable crash. This can occur during browser shutdown when reference decrementing happens on a previously freed object.
**Recommendations**
For Firefox versions prior to 83, update to version 83 or later to resolve the issue.
For Firefox ESR versions prior to 78.5, update to version 78.5 or later to resolve the issue.
For Thunderbird versions prior to 78.5, update to version 78.5 or later to resolve the issue.