This indicates an attack attempt to exploit a Out of Bound read vulnerability in Adobe Flash Player.
The vulnerability is due to an error when the vulnerable software handles a maliciously crafted SWF file. A remote attacker may be able to exploit this to access sensitives data, via a crafted SWF file.
Adobe Flash Player Desktop Runtime 126.96.36.199 on Windows and Macintosh
Adobe Flash Player for Google Chrome 188.8.131.52 on Windows, Macintosh, Linux and ChromeOS
Adobe Flash Player for Microsoft Edge and Internet Explorer 11 184.108.40.206 on Windows 10 and 8.1
Adobe Flash Player for Linux 220.127.116.11 on Linux
Information Disclosure: Remote attackers can gain sensitive information from vulnerable systems
Apply the most recent upgrade or patch from the vendor.