Vulnerability · Published Feb 18, 2026 · Assigned by GitHub_P
CVE-2026-1355Missing Authorization Check in GitHub Enterprise Server Allows Unauthorized Uploads to Repository Migration Exports
Medium 6.0
In plain English
A medium-severity missing authorization in Enterprise Server from GitHub. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).
Official 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 products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| GitHub | Enterprise Server | 3.19.0 – through 3.19.13.18.0 – through 3.18.43.17.0 – through 3.17.103.16.0 – through 3.16.133.15.0 – through 3.15.173.14.0 – through 3.14.22 |
Weakness: CWE-862 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:L
References
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.2
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.5
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.11
- https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.14
- https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.18
- https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.23