# CVE-2026-1355: Missing Authorization Check in GitHub Enterprise Server Allows Unauthorized Uploads to Repository Migration Exports

> CVE-2026-1355: Missing Authorization Check in GitHub Enterprise Server Allows Unauthorized Uploads to Repository Migration Exports. CVSS 6.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-1355
Last updated: 2026-06-17T10:15:39Z

- Published: 2026-02-18 20:42 UTC · Updated: 2026-06-17 10:15 UTC · Assigner: GitHub\_P
- CVSS: 6.5 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
- EPSS: 0.46%, 39th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-862

## 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.

## Affected vendors and products

- GitHub: Enterprise Server

## Tracked companies

- [GitHub](https://rewindex.com/company/github.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-1355)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-1355)
- [https://docs.github.com/en/enterprise-server@3.14/admin/release-notes\#3.14.23](https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.23)
- [https://docs.github.com/en/enterprise-server@3.15/admin/release-notes\#3.15.18](https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.18)
- [https://docs.github.com/en/enterprise-server@3.16/admin/release-notes\#3.16.14](https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.14)
- [https://docs.github.com/en/enterprise-server@3.17/admin/release-notes\#3.17.11](https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.11)
- [https://docs.github.com/en/enterprise-server@3.18/admin/release-notes\#3.18.5](https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.5)
- [https://docs.github.com/en/enterprise-server@3.19/admin/release-notes\#3.19.2](https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.2)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-1355 · Markdown: https://rewindex.com/cve/CVE-2026-1355.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-1355 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:10:10.923Z