Mozilla · Firefox Esr · CVE-2018-18500
**Name of the Vulnerable Software and Affected Versions**
Firefox versions prior to 65
Firefox ESR versions prior to 60.5
Thunderbird versions prior to 60.5
**Description**
The issue is related to a use-after-free vulnerability that can occur while parsing an HTML5 stream with custom HTML elements. This results in the stream parser object being freed while still in use, potentially leading to a crash. The vulnerability can be exploited by a remote attacker using a specially crafted web page, allowing them to execute arbitrary code or cause a denial of service.
**Recommendations**
For Firefox versions prior to 65, update to version 65 or later to resolve the issue.
For Firefox ESR versions prior to 60.5, update to version 60.5 or later to resolve the issue.
For Thunderbird versions prior to 60.5, update to version 60.5 or later to resolve the issue.