CVE-2026-103620
mediumA missing authorization vulnerability was identified in GitHub Enterprise Server that allowed a repository collaborator with write access to delete the current…
Vendor / product: Github — enterprise server
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.16 product-cna@github.com
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.13 product-cna@github.com
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.9 product-cna@github.com
- https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.7 product-cna@github.com
- https://docs.github.com/en/enterprise-server@3.22/admin/release-notes#3.22.2 product-cna@github.com