CVE-2026-5845 Improper authorization fallback allows scoped user-to-server token installation escape in GitHub Enterprise Server
Authenticated attackers can access and modify private repositories outside their token scope due to improper authorization fallback logic in GitHub Enterprise Server.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-5845?
CVE-2026-5845 is a high-severity missing authorization vulnerability in Github Enterprise Server, published on 21 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An improper authorization vulnerability in scoped user-to-server (ghu_) token authorization in GitHub Enterprise Server allows an authenticated attacker to access private repositories outside the intended installation scope, which can include write operations, via an authorization fallback that treated a revoked/deleted installation as a global installation context, which could be chained with token revocation timing and SSH push attribution to obtain and reuse a victim-scoped token. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, and 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program.
Weakness: CWE-639
Which versions are affected by CVE-2026-5845?
It affects 1 product.
Products include Github Enterprise Server.
How do I fix CVE-2026-5845?
No fix has been published for CVE-2026-5845 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-2026-5845 being exploited?
There is no known exploitation of CVE-2026-5845 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-29qm-pmxx-2p86.