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Mallory
Critical

Pre-authentication SSRF in GitHub Enterprise Server upload endpoint

IdentifiersCVE-2026-9312CWE-918· Server-Side Request Forgery (SSRF)

CVE-2026-9312 is a server-side request forgery vulnerability in GitHub Enterprise Server (GHES) affecting versions prior to 3.22. The flaw exists in an upload endpoint where insufficient input validation allows an unauthenticated attacker to submit crafted request parameters containing path traversal content. By abusing this validation gap, the attacker can bypass the intended request flow and cause the server to issue internal API or HTTP requests to unintended internal destinations. The issue is described as pre-authentication and network-reachable, meaning exploitation does not require a valid account if the vulnerable endpoint is exposed. The vulnerable behavior can redirect internal calls and enable access to internal services that are not normally reachable by external users, with potential exposure of sensitive credentials or related internal data.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an unauthenticated remote attacker to coerce the GHES appliance into making attacker-influenced requests to internal services. This can expose otherwise non-public internal endpoints, internal API responses, configuration data, or sensitive credentials reachable from the appliance. Because the flaw is pre-authentication, it materially increases risk for internet-facing or otherwise untrusted-network-exposed GHES deployments. Depending on what internal services are reachable from the appliance, the vulnerability may enable internal service enumeration, access to privileged metadata or secrets, and follow-on compromise of enterprise infrastructure.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure of the vulnerable upload endpoint to untrusted networks, restrict network access to GHES to trusted administrative or user populations, and apply network segmentation/egress controls so the appliance cannot freely reach sensitive internal services. Review and limit access to internal services, upload-related endpoints, and any paths that could be reached from the GHES host. These measures are compensating controls only; vendor patching is the primary remediation.

Remediation

Patch, then assume compromise.

Upgrade GitHub Enterprise Server to a fixed release. The provided advisory states affected versions prior to 3.22 should be updated to 3.16.20, 3.17.17, 3.18.11, 3.19.8, 3.20.4, 3.21.1, or a later fixed version. Supporting content also indicates GitHub tightened input validation and restricted reachable destinations from the affected endpoint as part of the fix. Apply the vendor update on all affected appliances, prioritizing internet-facing instances.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
GitHubEnterprise Serverapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity5

Community discussion across Reddit, Mastodon, and other social sources.