CVE-2026-1355: Missing Authorization Check in GitHub Enterprise Server Allows Unauthorized Uploads to Repository Migration Exports
Description
A Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to upload unauthorized content to another user’s repository migration export due to a missing authorization check in the repository migration upload endpoint. By supplying the migration identifier, an attacker could overwrite or replace a victim’s migration archive, potentially causing victims to download attacker-controlled repository data during migration restores or automated imports. An attacker would require authentication to the victim's GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.20 and was fixed in versions 3.19.2, 3.18.5, 3.17.11, 3.16.14, 3.15.18, 3.14.23. This vulnerability was reported via the GitHub Bug Bounty program.
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N · CWE-862
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
GitHub: Enterprise Server
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- docs.github.com/en/enterprise-server@3.14/admin/release-notes (opens in new tab)
- docs.github.com/en/enterprise-server@3.15/admin/release-notes (opens in new tab)
- docs.github.com/en/enterprise-server@3.16/admin/release-notes (opens in new tab)
- docs.github.com/en/enterprise-server@3.17/admin/release-notes (opens in new tab)
- docs.github.com/en/enterprise-server@3.18/admin/release-notes (opens in new tab)
- docs.github.com/en/enterprise-server@3.19/admin/release-notes (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)