CVE-2026-15996
highpriority · track · 30EPSS 0.008 · 55 %ileEUUSEPSS · scored 2026-10-27
A denial of service vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause excessive CPU consumption and exhaust the pool of request-handling worker processes by sending a crafted form-encoded HTTP POST request containing deeply nested parameters. Because request parameters were parsed before routing and authentication, any POST endpoint could be used to trigger the condition, which could render the instance unresponsive. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.3, 3.19.7, 3.18.10, and 3.17.16.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–7.5
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (8)
Products and version ranges known to be affected.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (12)
External citations — patches, advisories, analysis.
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.16cnnvd
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.10cnnvd
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.7cnnvd
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.3cnnvd
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.16enisa_euvd
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.10enisa_euvd
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.7enisa_euvd
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.3enisa_euvd
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