Vulnerability · Published Jul 17, 2026 · Assigned by GitHub_P
CVE-2026-15007Denial of service vulnerability in GitHub Enterprise Server allowed service disruption via deeply nested YAML in release notes configuration
Medium 5.7
In plain English
A medium-severity resource allocation without limits in Enterprise Server from GitHub. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 51% of all known vulnerabilities).
Official description
A denial of service vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to cause service disruption by supplying a repository release notes configuration file containing deeply nested YAML. When release notes were generated, the configuration file was parsed without a nesting depth limit, causing excessive resource consumption that could render the instance unresponsive. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.18, 3.18.12, 3.19.9, 3.20.5, and 3.21.3. This vulnerability was reported via the GitHub Bug Bounty program.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| GitHub | Enterprise Server | 3.17.0 – through 3.17.173.18.0 – through 3.18.113.19.0 – through 3.19.83.20.0 – through 3.20.43.21.0 – through 3.21.2 |
Weakness: CWE-770 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:U
References
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.18 release-notes
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.12 release-notes
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.9 release-notes
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.5 release-notes
- https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.3 release-notes