CVE-2026-1355 Missing Authorization Check in GitHub Enterprise Server Allows Unauthorized Uploads to Repository Migration Exports
Authenticated attackers can overwrite repository migration exports, causing victims to download attacker-controlled data during restores.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-1355?
CVE-2026-1355 is a medium-severity missing authorization vulnerability in Github Enterprise Server, published on 18 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Weakness: CWE-862
Which versions are affected by CVE-2026-1355?
It affects 1 product.
Products include Github Enterprise Server.
How do I fix CVE-2026-1355?
No fix has been published for CVE-2026-1355 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-1355 being exploited?
There is no known exploitation of CVE-2026-1355 in the wild and no public exploit code.
Other vulnerabilities in Github Enterprise Server
- CVE-2024-4985 Auth bypass in Enterprise Server
- CVE-2022-23739 Missing authorization in GitHub Enterprise Server
- CVE-2022-46255 Improper Limitation of a Pathname to a Restricted Directory in GitHub Enterprise Server leading to RCE
- CVE-2021-22869 Improper access control in GitHub Enterprise Server allows self-hosted runners to execute outside their control group
- CVE-2024-9487 Auth bypass in Enterprise Server
Sources
Also known as GHSA-2q3j-wj77-9934.