The remote Debian host is missing a security-related update.
Several vulnerabilities have been discovered in the OpenJDK Java runtime, resulting in information disclosure, denial of service or bypass of sandbox restrictions. In addition the implementation of elliptic curve cryptography was modernised.
Upgrade the openjdk-8 packages. For the oldstable distribution (stretch), these problems have been fixed in version 8u222-b10-1~deb9u1.