CVE-2026-15007
Denial of service vulnerability in GitHub Enterprise Server allowed service disruption via deeply nested YAML in release notes configuration
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.
INFO
Published Date :
July 17, 2026, 4:17 p.m.
Last Modified :
July 17, 2026, 5:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | MEDIUM | 82327ea3-741d-41e4-88f8-2cf9e791e760 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update GitHub Enterprise Server to a fixed version.
- Apply the latest security patches for your version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-15007.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-15007 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-15007
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-15007 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-15007 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-15007', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-17T16:35:53.532624Z'} -
New CVE Received by [email protected]
Jul. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'GitHub', 'product': 'Enterprise Server', 'versions': [{'status': 'affected', 'changes': [{'at': '3.17.18', 'status': 'unaffected'}], 'version': '3.17.0', 'versionType': 'semver', 'lessThanOrEqual': '3.17.17'}, {'status': 'affected', 'changes': [{'at': '3.18.12', 'status': 'unaffected'}], 'version': '3.18.0', 'versionType': 'semver', 'lessThanOrEqual': '3.18.11'}, {'status': 'affected', 'changes': [{'at': '3.19.9', 'status': 'unaffected'}], 'version': '3.19.0', 'versionType': 'semver', 'lessThanOrEqual': '3.19.8'}, {'status': 'affected', 'changes': [{'at': '3.20.5', 'status': 'unaffected'}], 'version': '3.20.0', 'versionType': 'semver', 'lessThanOrEqual': '3.20.4'}, {'status': 'affected', 'changes': [{'at': '3.21.3', 'status': 'unaffected'}], 'version': '3.21.0', 'versionType': 'semver', 'lessThanOrEqual': '3.21.2'}], 'defaultStatus': 'affected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-770 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.17.18 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.18.12 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.19.9 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.20.5 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.21.3