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

Exploitation

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

CVSS

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

EPSS

• CVE-2026-54690: 0.39% estimated exploitation activity in the next 30 days; percentile 32.98 (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 JSON-Schema $ref values pointing at HTTP or HTTPS URLs are silently dereferenced by datamodel-code-generator with no IP/host validation, no scheme allow-list, and redirects followed unconditionally. The --allow-remote-refs gate added in 0.56.0 defaults to None, which only emits a deprecation warning and then fetches the URL anyway; only explicit --allow-remote-refs=false blocks the request. The fetched body is parsed as a sub-schema and reflected verbatim into the generated .py source. As a result, any JSON-Schema document the developer feeds to datamodel-codegen — including documents authored by an attacker — can pivot to arbitrary internal addresses and leak the response into the generated code, with no developer cooperation beyond running the tool. Details Sink: src/datamodelcodegenerator/parser/jsonschema.py, getrefbody (lines 4776–4793, at tag 0.60.1 / commit a321547e): - (A) emits a deprecation warning when allowremoterefs is its default (None); execution falls through…

Published by the source

28 Jul 2026, 21:42 UTC

Last modified by the source

28 Jul 2026, 21:42 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-954p-556p-r752

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-54690

Advisory: datamodel-code-generator vulnerable to SSRF via JSON-Schema `$ref` to HTTP URL (silent by default)
IDs: CVE-2026-54690, GHSA-954p-556p-r752
Record: https://patchnext.com/advisories/cve-2026-54690 (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 8.2)
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 0.61.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI datamodel-code-generator: affected >= 0.9.1, <= 0.60.2; fixed in 0.61.0

## 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-954p-556p-r752 (GitHub-reviewed advisory GHSA-954p-556p-r752 lists affected ranges: PyPI datamodel-code-generator >=0.9.1 <=0.60.2)

Commands are suggestions: review each one before running it.