Updated jruby packages has been released for Debian GNU/Linux 8 LTS

Package : jruby
Version : 1.5.6-9+deb8u2
CVE ID : CVE-2017-17742 CVE-2019-16201 CVE-2019-16254
CVE-2019-16255

Several security vulnerabilities were found in Ruby that also affected
Debian's JRuby package, a pure-Java implementation of Ruby. Attackers
were able to call arbitrary Ruby methods, cause a denial-of-service or
inject input into HTTP response headers when using the WEBrick module.

For Debian 8 "Jessie", these problems have been fixed in version
1.5.6-9+deb8u2.

We recommend that you upgrade your jruby packages.

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS