# CVE-2026-18730: Server-side request forgery vulnerability in GitHub Enterprise Server Manage API leaked a replayable gateway-agent bearer token

> CVE-2026-18730: Server-side request forgery vulnerability in GitHub Enterprise Server Manage API leaked a replayable gateway-agent bearer token. CVSS 7.4 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-18730
Last updated: 2026-09-22T21:17:30Z

- Published: 2026-09-01 21:54 UTC · Updated: 2026-09-22 21:17 UTC · Assigner: GitHub\_P
- CVSS: 7.4 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
- EPSS: 0.49%, 41th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-918

## 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.

## Affected vendors and products

- GitHub: Enterprise Server

## Tracked companies

- [GitHub](https://rewindex.com/company/github.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-18730)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-18730)
- [https://docs.github.com/en/enterprise-server@3.17/admin/release-notes\#3.17.21](https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.21)
- [https://docs.github.com/en/enterprise-server@3.18/admin/release-notes\#3.18.15](https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.15)
- [https://docs.github.com/en/enterprise-server@3.19/admin/release-notes\#3.19.12](https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.12)
- [https://docs.github.com/en/enterprise-server@3.20/admin/release-notes\#3.20.8](https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.8)
- [https://docs.github.com/en/enterprise-server@3.21/admin/release-notes\#3.21.6](https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.6)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-18730 · Markdown: https://rewindex.com/cve/CVE-2026-18730.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-18730 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:16:54.407Z