CVE-2016-7855

Adobe Flash Player for Windows, macOS/OS X, and Linux contains a use-after-free memory flaw (CWE-416) in which memory that has been freed is referenced again, corrupting memory when the player processes attacker-controlled Flash content remotely, typically via a malicious SWF delivered through a browser or another host application. A successful attack allows arbitrary code execution with the privileges of the user running Flash, commonly leading to full workstation compromise in browsing contexts. Anyone still running an affected Adobe Flash Player build is exposed, although the product has been end-of-life since early 2021 and CISA explicitly advises disconnecting or removing it rather than continuing to patch. The flaw is listed in CISA's Known Exploited Vulnerabilities catalog (added March 3, 2022), confirming known in-the-wild exploitation, and EPSS assigns a 25.2% probability of exploitation within 30 days (98th percentile); no public proof-of-concept is known and ransomware use is unknown.

What to do: Because Flash Player is end-of-life and no longer receives security updates, follow CISA's required action: uninstall or disable Flash everywhere it remains, including browser plugins, standalone installs, and legacy applications that invoke it. If removal must be delayed, ensure the latest patched release from Adobe's security advisories is in place and block or sandbox untrusted Flash content. On systems where Flash is still active, hunt for indicators of compromise given the KEV listing and high EPSS score.