The Microsoft Foundation released several security vulnerability fixes for the Firefox. Firefox ESR, and thunderbird. It is recommended to take the necessary precautions by ensuring products are always updated to avoid an attacker from exploiting one of these vulnerabilities by taking control of an affected system.
Mozilla Foundation Security Advisory 2019-13
Mozilla Release Security updates for Firefox includes: 2 Critical, 11 High, 6 Medium, and 2 low vulnerability fixes.
The Guyana National CIRT recommends that users and administration review these updates and apply them where necessary.
Microsoft Releases Security Updates to Address Remote Code Execution Vulnerability (US-Cert)