CVE-2026-18730 Server-side request forgery in Enterprise Server
Unauthenticated attackers can exploit SSRF to capture replayable bearer tokens, enabling access to privileged management agent endpoints.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-18730?
CVE-2026-18730 is a high-severity server-side request forgery vulnerability in Github Enterprise Server, published on 1 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A server-side request forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause the Manage API to send crafted outbound requests to an attacker-controlled host. An unauthenticated endpoint parsed an attacker-supplied cluster configuration and issued gateway-to-agent requests whose HMAC authenticated only a timestamp, not the request path or body. An attacker positioned to intercept the outbound request could capture this token and replay it against privileged management agent endpoints. High-availability deployments were not affected due to a topology restriction. This vulnerability affected GitHub Enterprise Server releases in the 3.17, 3.18, 3.19, 3.20, and 3.21 series and was fixed in versions 3.17.21, 3.18.15, 3.19.12, 3.20.8, and 3.21.6. This vulnerability was reported via the GitHub Bug Bounty program.
Weakness: CWE-918
Which versions are affected by CVE-2026-18730?
It affects 1 product.
Products include Github Enterprise Server.
How do I fix CVE-2026-18730?
No fix has been published for CVE-2026-18730 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-18730 being exploited?
There is no known exploitation of CVE-2026-18730 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-xh7g-7v3x-h73p.