CVE-2026-15007

Denial of service vulnerability in GitHub Enterprise Server allowed service disruption via deeply nested YAML in release notes configuration

MEDIUM
5.7
CVSS Score
Published: July 17, 2026 at 03:16 PM UTC
Updated: October 24, 2026 at 08:10 PM UTC
1 product affected across 1 vendorGitHub Enterprise Server

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Severity
MEDIUM5.7
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

3.17.0 ≤ v ≤ 3.17.173.18.0 ≤ v ≤ 3.18.113.19.0 ≤ v ≤ 3.19.83.20.0 ≤ v ≤ 3.20.43.21.0 ≤ v ≤ 3.21.23.17.03.18.03.19.03.20.03.21.0

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.7MEDIUMGitHub_P
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-770

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