A deserialization of untrusted data vulnerability was identified in GitHub Enterprise Server that could potentially lead to remote code execution on the SVNBridge. To exploit this vulnerability, an attacker would need to gain access via a server-side request forgery (SSRF) that would let an attacker control the data being deserialized. This vulnerability affected all versions of GitHub Enterprise Server prior to v3.6 and was fixed in versions 3.5.3, 3.4.6, 3.3.11, and 3.2.16. This vulnerability was reported via the GitHub Bug Bounty program.
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.