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.
Fix
Patch, vendor advisory and mitigation references on NVD 5
- https://docs.github.com/en/[email protected]/admin/release-notes#3.16.18 Release Notes, Vendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.17.15 Release Notes, Vendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.18.9 Release Notes, Vendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.6 Release Notes, Vendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.20.2 Release Notes, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 6.3 · githubNVD modified 2026-10-26 20:10
Affected (CPE criteria) 1
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
References 5
- https://docs.github.com/en/[email protected]/admin/release-notes#3.16.18 Release Notes, Vendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.17.15 Release Notes, Vendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.18.9 Release Notes, Vendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.6 Release Notes, Vendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.20.2 Release Notes, Vendor Advisory