Java serialization allows objects to be converted into byte streams for transmission or storage. Java 7u80 fails to properly validate untrusted serialized data during deserialization.

Since 7u80 was the final public release, any vulnerability found in the "Java 7" family since 2015 technically applies to an unpatched 7u80 installation. Some significant historical and post-EOL issues include:

Use a WAF or Intrusion Prevention System (IPS) to detect and block known Java serialization gadget chains and RCE exploit payloads before they reach the server.

The risk assessment for these vulnerabilities varies, but generally, they can be categorized as: