CVE-2026-54690

datamodel-code-generator vulnerable to SSRF via JSON-Schema $ref to HTTP URL (silent by default)

def _get_ref_body(self, resolved_ref: str) -> dict[str, YamlValue]:
    if is_url(resolved_ref):
        if not resolved_ref.startswith("file://") and self.http_local_ref_path is None:
            if self.allow_remote_refs is False:
                raise Error(f"Fetching remote $ref is disabled: {resolved_ref}...")
            if self.allow_remote_refs is None:
                warn_deprecated(                            # (A) warn only
                    "behavior.remote-ref-default",
                    details=f"Reference: {resolved_ref}",
                    stacklevel=2,
                )
        return self._get_ref_body_from_url(resolved_ref)    # (B) fetch fires
    return self._get_ref_body_from_remote(resolved_ref)

Who is impacted. Anyone running datamodel-codegen on a JSON-Schema or OpenAPI document of uncertain provenance, with the [http] extra installed. Real-world scenarios:

1. Trojaned OpenAPI document. A public REST API publishes openapi.yaml. One $ref points at http://169.254.169.254/latest/meta-data/iam/security-credentials/<role>; running datamodel-codegen against the spec from an EC2 instance leaks the IAM credentials into the generated client.
2. Customer-supplied JSON Schema. A B2B SaaS auto-generates client code from customer-uploaded schemas. The customer adds an HTTP $ref to http://internal-admin:8080/users.json; the response (e.g. JSON user list) ends up in the generated Python the SaaS hands back to the customer.
3. CI on a private network. A PR adds schemas/inbound.json with an HTTP $ref pointed at a service reachable only from the CI cluster's VPC; the CI runner fetches it and the generated .py leaks the response in PR artifacts.

Higher real-world risk than the sibling CLI-flag SSRF (other SSRF in this report bundle) because the schema author chooses the destination, the developer doesn't have to type any URL.

Suggested fix.

1. Flip the default in parser/base.py: allow_remote_refs: bool = False, and remove the silent-fetch-with-warning fallback at parser/jsonschema.py:4786-4791.
2. When fetching is allowed, apply the same IP/host validation proposed for other submitted SSRF report to both the initial $ref URL and every redirect target.
3. Document HTTP $ref in a third-party schema as equivalent to running curl on the developer's host.

Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside. Typical impact: access to internal metadata services, internal APIs, or cloud credentials.

CVE-2026-54690 has a CVSS score of 8.2 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.61.0); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

1. What is CVE-2026-54690? CVE-2026-54690 is a high-severity server-side request forgery (SSRF) vulnerability in datamodel-code-generator (pip), affecting versions >= 0.9.1, <= 0.60.2. It is fixed in 0.61.0. Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside.
2. How severe is CVE-2026-54690? CVE-2026-54690 has a CVSS score of 8.2 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of datamodel-code-generator are affected by CVE-2026-54690? datamodel-code-generator (pip) versions >= 0.9.1, <= 0.60.2 is affected.
4. Is there a fix for CVE-2026-54690? Yes. CVE-2026-54690 is fixed in 0.61.0. Upgrade to this version or later.
5. Is CVE-2026-54690 exploitable, and should I be worried? Whether CVE-2026-54690 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-54690 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-54690? Upgrade datamodel-code-generator to 0.61.0 or later.

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