Recent CVEs
CVE-2017-0903
RubyGems versions between 2.0.0 and 2.6.13 are vulnerable to a possible remote code execution vulnerability. YAML deserialization of gem specifications can bypass class white lists. Specially crafted serialized objects can possibly be used to escalate to remote code execution.
CVE-2017-0902
RubyGems version 2.6.12 and earlier is vulnerable to a DNS hijacking vulnerability that allows a MITM attacker to force the RubyGems client to download and install gems from a server that the attacker controls.
CVE-2017-0899
RubyGems version 2.6.12 and earlier is vulnerable to maliciously crafted gem specifications that include terminal escape characters. Printing the gem specification would execute terminal escape sequences.
CVE-2017-0901
RubyGems version 2.6.12 and earlier fails to validate specification names, allowing a maliciously crafted gem to potentially overwrite any file on the filesystem.