datamodel-code-generator vulnerable to arbitrary local file read via JSON-Schema $ref (file:// and ../ traversal), bypassing --no-allow-remote-refs

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-55389: 0.55% estimated exploitation activity in the next 30 days; percentile 45.90 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary datamodel-code-generator resolves JSON-Schema $ref targets that point at the local filesystem without restricting them to the input/base directory and without honoring the remote-reference security control. In the default configuration, an attacker who controls an input schema (a "paste your OpenAPI/JSON-Schema" service, a CI job that generates models from a submitted spec, or any multi-tenant codegen platform) can read any file the process user can read and map the host filesystem. This works via either a file:// absolute URI or a ../-escaped relative reference, and it succeeds even when --no-allow-remote-refs is set. This is an unauthenticated path-traversal / information-disclosure issue (CWE-22 / CWE-200) plus a bypass of a documented security control. Details isurl() classifies file:// as a URL (reference.py:1249): The remote-ref gate then explicitly exempts file://, so --no-allow-remote-refs never applies to it (parser/jsonschema.py, getrefbody): Both local-file…

Published by the source

28 Jul 2026, 21:49 UTC

Last modified by the source

28 Jul 2026, 21:49 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8359-h9fx-j6v9

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# Patch Next advisory brief: CVE-2026-55389

Advisory: datamodel-code-generator vulnerable to arbitrary local file read via JSON-Schema `$ref` (`file://` and `../` traversal), bypassing `--no-allow-remote-refs`
IDs: CVE-2026-55389, GHSA-8359-h9fx-j6v9
Record: https://patchnext.com/advisories/cve-2026-55389 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: datamodel-code-generator 0.62.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI datamodel-code-generator: affected <= 0.61.0; fixed in 0.62.0

## Suggested inspection (read-only)
- `python -m pip show datamodel-code-generator`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on datamodel-code-generator.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-8359-h9fx-j6v9 (GitHub-reviewed advisory GHSA-8359-h9fx-j6v9 lists affected ranges: PyPI datamodel-code-generator >=0 <=0.61.0)

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