Adobe released a security update yesterday that resolves a critical vulnerability in Flash Player that could allow malicious sites to execute code on your computer. This vulnerability has a CVE ID of CVE-2018-15981 and is a Type Confusion vulnerability that allows remote code execution. A security update for Adobe Flash Player was already released this month on November 13th along with updates for other products. The reason Adobe has released another update is because the technical information regarding this vulnerability has already been posted online and could be used by attackers to create a working exploit.
Source: https://www.bleepingcomputer.com/news/security/adobe-flash-player-update-released-for-remote-code-execution-vulnerability/