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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-1999 Detail

Description

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to merge their own pull request into a repository without having push access by exploiting an authorization bypass in the enable_auto_merge mutation for pull requests. This issue only affected repositories that allow forking as the attack relies on opening a pull request from an attacker-controlled fork into the target repository. Exploitation was only possible in specific scenarios. It required a clean pull request status and only applied to branches without branch protection rules enabled. This vulnerability affected GitHub Enterprise Server versions prior to 3.19.2, 3.18.5, and 3.17.11, and was fixed in versions 3.19.2, 3.18.5, and 3.17.11. This vulnerability was reported via the GitHub Bug Bounty program.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc. (Products Only)
CVSS-B 7.1 HIGH
Vector:  CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:L/SI:H/SA:N

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://docs.github.com/en/[email protected]/admin/release-notes#3.17.11 GitHub, Inc. (Products Only)
https://docs.github.com/en/[email protected]/admin/release-notes#3.18.5 GitHub, Inc. (Products Only)
https://docs.github.com/en/[email protected]/admin/release-notes#3.19.2 GitHub, Inc. (Products Only)

Weakness Enumeration

CWE-ID CWE Name Source
CWE-863 Incorrect Authorization GitHub, Inc. (Products Only)  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-1999
NVD Published Date:
02/18/2026
NVD Last Modified:
02/18/2026
Source:
GitHub, Inc. (Products Only)