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CVE-2026-18730

7.4, high

GitHub Enterprise Server Server-Side Request Forgery Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab)
CVSS
7.4, high high CVSS v3.1
EPSS, next 30 days
0.3% higher than 20.2% of scored CVEs
Exploitation
No public evidence
Published
1 Sept 2026a month ago

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.

Details

Vendor
GitHub
Product
Enterprise Server
Weakness
CWE-918 (opens in a new tab)
Status
Modified
Updated
22 Sept 2026
Assigner
product-cna@github.com

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

References 5

Other references 5

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other GitHub CVEs

Every GitHub CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-96890 GitHub Enterprise Server Server-Side Request Forgery Vulnerability EPSS 0.5% 8.8, high
  • CVE-2026-77987 A server-side request forgery (SSRF) vulnerability was identified in the notebook viewer of GitHub Enterprise Server EPSS 0.9% 9.8, critical
  • CVE-2026-19118 GitHub Enterprise Server Time-of-Check Time-of-Use Race Condition Vulnerability EPSS 0.7% 7.5, high
  • CVE-2026-76851 GitHub Enterprise Server Server-Side Request Forgery Vulnerability EPSS 0.8% 8.8, high

Beyond this page

Is CVE-2026-18730 in your network?

This page tells you how dangerous CVE-2026-18730 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

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Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 16 Oct 2026, not the live upstream state.