CVE-2026-18730

HIGH CVSS 4.0: 8.2 EPSS 0.29%
Updated Sep 10, 2026
GitHub
Parameter Value
CVSS 8.2 (HIGH)
Affected Versions 3.18.0 — 3.21.4
Fixed In 3.17.19
Type CWE-918 (Server-Side Request Forgery (SSRF))
Vendor GitHub
Public PoC No

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 all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.19, 3.18.13, 3.19.10, 3.20.6, and 3.21.4. This vulnerability was reported via the GitHub Bug Bounty program.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
None
No data modification
Availability
None
No disruption

CVSS Vector v4.0

Vulnerable Products 5

Configuration From (including) Up to (excluding)
Github Enterprise_Server
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
3.17.19
Github Enterprise_Server
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
3.18.0 3.18.13
Github Enterprise_Server
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
3.19.0 3.19.10
Github Enterprise_Server
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
3.20.0 3.20.6
Github Enterprise_Server
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
3.21.0 3.21.4