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CVE-2026-103620

Missing authorization in GitHub Enterprise Server allowed repository writers to replace default branches via GraphQL

A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed a repository collaborator with write access to delete the current default branch through the GraphQL API and cause an attacker-controlled branch to become the new default. In repositories that required pull-request review but did not restrict branch deletion, this bypassed the review requirement and caused fresh clones and default-branch API requests to use attacker-controlled content. This vulnerability affected supported GitHub Enterprise Server releases in the 3.18, 3.19, 3.20, 3.21, and 3.22 series and was fixed in versions 3.18.16, 3.19.13, 3.20.9, 3.21.7, and 3.22.2. This vulnerability was reported via the GitHub Bug Bounty program.
Daten sind bereitgestellt durch das CVE Programm von einer CVE Numbering Authority (CNA) (Unstrukturiert).
HerstellerGitHub
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Produkt Enterprise Server
Default Statusunknown
Version 3.18.0
Version < 3.18.*
Status affected
Version 3.19.0
Version < 3.19.*
Status affected
Version 3.20.0
Version < 3.20.*
Status affected
Version 3.21.0
Version < 3.21.*
Status affected
Version 3.22.0
Version < 3.22.*
Status affected
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.45% 0.37
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
product-cna@github.com 6 0 0
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/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
CWE-862 Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.16
https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.13
https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.9
https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.7
https://docs.github.com/en/enterprise-server@3.22/admin/release-notes#3.22.2