GitHub Enterprise Server up to 3.21.0 server-side request forgery

Summaryinfo

A vulnerability classified as critical has been found in GitHub Enterprise Server up to 3.21.0. This impacts an unknown function. Performing a manipulation results in server-side request forgery. This vulnerability is reported as CVE-2026-8606. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in GitHub Enterprise Server up to 3.21.0. It has been classified as critical. This affects some unknown processing. The manipulation with an unknown input leads to a server-side request forgery vulnerability. CWE is classifying the issue as CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

A Server-Side Request Forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed an attacker to cause the server to issue HTTP requests to internal services via the security advisories package lookup feature. By directing requests to an internal management service and measuring response timing, an attacker could infer the values of sensitive environment variables, including signing secrets and private keys. Exploitation required GitHub Packages to be enabled; on instances not running in private mode the vulnerability was exploitable without authentication, otherwise any authenticated user could exploit it. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21.1 and was fixed in versions 3.20.3, 3.19.7, 3.18.10, 3.17.16, and 3.16.19. This vulnerability was reported via the GitHub Bug Bounty program.

The weakness was disclosed by R31n. It is possible to read the advisory at docs.github.com. This vulnerability is uniquely identified as CVE-2026-8606 since 05/14/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 3.21.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CNNVD (CNNVD-202605-6105). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Bug Tracking Software

Vendor

• GitHub

Name

• Enterprise Server

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8
• 3.9
• 3.10
• 3.11
• 3.12
• 3.13
• 3.14
• 3.15
• 3.16
• 3.16.0
• 3.16.1
• 3.16.2
• 3.16.3
• 3.16.4
• 3.16.5
• 3.16.6
• 3.16.7
• 3.16.8
• 3.16.9
• 3.16.10
• 3.16.11
• 3.16.12
• 3.16.13
• 3.16.14
• 3.16.15
• 3.16.16
• 3.16.17
• 3.16.18
• 3.17
• 3.17.0
• 3.17.1
• 3.17.2
• 3.17.3
• 3.17.4
• 3.17.5
• 3.17.6
• 3.17.7
• 3.17.8
• 3.17.9
• 3.17.10
• 3.17.11
• 3.17.12
• 3.17.13
• 3.17.14
• 3.17.15
• 3.18
• 3.18.0
• 3.18.1
• 3.18.2
• 3.18.3
• 3.18.4
• 3.18.5
• 3.18.6
• 3.18.7
• 3.18.8
• 3.18.9
• 3.19
• 3.19.0
• 3.19.1
• 3.19.2
• 3.19.3
• 3.19.4
• 3.19.5
• 3.19.6
• 3.20
• 3.20.0
• 3.20.1
• 3.20.2
• 3.21.0

License

• open-source

CPE 2.3info

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CPE 2.2info

• 🔒
• 🔒
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Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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