Vulnerability Advisory : Denial of service vulnerability in GitHub Enterprise Server allowed service disruption via unauthenticated API endpoint with LOW Attack Complexity

A denial of service vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause service disruption by sending crafted requests with deeply nested JSON payloads to an unauthenticated API endpoint. The endpoint parsed user-controlled JSON request bodies without size or depth limits, causing excessive CPU and memory consumption. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.2, 3.19.6, 3.18.9, 3.17.15, and 3.16.18. This vulnerability was reported via the GitHub Bug Bounty program.