In ruby-json before 2.3.0, there is an unsafe object creation vulnerability. When parsing certain JSON documents, the json gem (including the one bundled with Ruby) can be coerced into creating arbitrary objects in the target system.

For Debian 8 Jessie, this problem has been fixed in version 1.8.1-1+deb8u1.

We recommend that you upgrade your ruby-json 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