GitHub Enterprise Server: Server-Side Request Forgery in secret scanning
Summary
A Server-Side Request Forgery (SSRF) flaw in the secret scanning validator for GCP service account credentials of GitHub Enterprise Server allows an attacker to make the appliance send requests to internal hosts of their choice. A user who can push to a repository can commit crafted credentials whose token endpoint points to an internal destination. The vendor states this could potentially be chained to remote code execution on the appliance. Exploitation requires GitHub Advanced Security and secret scanning validity checks to be enabled, which are non-default settings.
Affected
- GitHub Enterprise Server 3.20, 3.21 and 3.22 (per the CVE record)
- Versions 3.18 and 3.19: unverified. An HKCERT bulletin lists fixes for these branches, so check the vendor advisory.
Fixed in
- GitHub Enterprise Server 3.20.9
- GitHub Enterprise Server 3.21.7
- GitHub Enterprise Server 3.22.2
Workaround
- The CVE record lists no workaround. Patching is the primary remedy.
- Interim option, not confirmed by the vendor: disable secret scanning validity checks until patching is possible. Test first, as this changes alert behavior.
Exploitation
- No known exploitation in the wild. CISA SSVC lists exploitation as none and automatable as no.
- The CVE is not listed in CISA KEV.
- No public proof of concept found. The RCE chain is not detailed in any source and is unverified.
Our recommendation
- Check whether you run GitHub Enterprise Server 3.20, 3.21 or 3.22 and whether secret scanning validity checks are enabled.
- Patch to 3.20.9, 3.21.7 or 3.22.2 or later.
- Until patched, restrict who can push to repositories and consider disabling validity checks.
- Check the vendor advisory for 3.18 and 3.19 before assuming you are unaffected.
- Monitor for unusual outbound requests from the appliance.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- GitHub Enterprise Server 3.20.9 release notes docs.github.com
- GitHub Enterprise Server 3.21.7 release notes docs.github.com
- GitHub Enterprise Server 3.22.2 release notes docs.github.com
- GitHub Enterprise Server 3.22 release notes docs.github.com
- OpenCVE entry CVE-2026-96890 app.opencve.io
- Vulners entry CVE-2026-96890 vulners.com
- Safeguard analysis CVE-2026-96890 safeguard.sh
- HKCERT security bulletin GitHub Enterprise Server www.hkcert.org
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 05:30.
Original description (NVD)
A Server-Side Request Forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed a repository contributor to cause the appliance to issue requests to attacker-controlled internal hosts, which could be chained to achieve remote code execution on the appliance. The secret scanning validator for GCP service account credentials trusted the token endpoint embedded in a committed credential and issued a request to it without restricting the destination. Exploitation required an authenticated user with permission to push to a repository on an instance with GitHub Advanced Security and secret scanning validity checks enabled, a non-default configuration. This vulnerability affected GitHub Enterprise Server 3.20, 3.21, and 3.22 and was fixed in versions 3.20.9, 3.21.7, and 3.22.2. This vulnerability was reported through the GitHub Bug Bounty program.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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