Opera has released a new version of its web browser version 12.13 and recommended that users update their installations to benefit from a series of security fixes as well as the usual stability enhancements The latest version of Opera for Windows, Mac and Linux is available for download from the Opera website. You can read about the fixed security issues (including a high severity vulnerability that could be exploited to cause the web browser to crash, and in some cases execute arbitrary code such as malware)”]
Source: https://grahamcluley.com/opera-security-mac-app-store/