Debian LTS: DLA-2392-1 Critical WEBrick Request Smuggling Issue

WEBrick (bundled along with jruby) was too tolerant against
an invalid Transfer-Encoding header. This may lead to
inconsistent interpretation between WEBrick and some HTTP proxy
servers, which may allow the attacker to “smuggle” a request.

For Debian 9 stretch, this problem has been fixed in version
1.7.26-1+deb9u3.

We recommend that you upgrade your jruby packages.

For the detailed security status of jruby please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/source-package/jruby

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