CVE-2026-15996
Medium
Elevated severity or exploit probability.
CVSS base
7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS — probability of exploitation (30 days)
0.8%
53.6th percentile
CISA KEV
Not listed
Weakness / dates
CWE-674
Published 2026-08-05 · modified 2026-08-18
Description
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.
Affected
References
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.16
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.10
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.7
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.3