Medium severity · published Jul 17, 2026
CVE-2026-15007
Denial of service vulnerability in GitHub Enterprise Server allowed service disruption via deeply nested YAML in release notes configuration
5.7
CVSS
0.6%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 50% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ES
Enterprise Server · GitHub
3.17.0 through 3.17.17; 3.18.0 through 3.18.11; 3.19.0 through 3.19.8; 3.20.0 through 3.20.4; 3.21.0 through 3.21.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-15007
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-15007
docs.github.com
https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.18
docs.github.com
https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.12
docs.github.com
https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.9
docs.github.com
https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.5
docs.github.com
https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.3
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