datamodel-code-generator vulnerable to code injection via unescaped carriage return in GraphQL Union description

Exploitation

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

CVSS

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

EPSS

• CVE-2026-54621: 0.21% estimated exploitation activity in the next 30 days; percentile 11.25 (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 is vulnerable to code injection when generating Python models from an attacker-controlled GraphQL schema. A description on a Union type, written in the regular-string form ("...") with a literal \r escape, is rendered into a Python

comment by a Jinja2 filter that handles only \n. Python's tokenizer treats a bare CR as a physical-line terminator, so the comment ends at the \r and the text after it is parsed as module-level Python. The injected code executes at import time of the generated .py, in the context of any consumer that imports the model. No special CLI flags are required. This affects versions =0.25.0, <0.60.1 and is fixed in 0.60.1. Details The vulnerable output was generated by the GraphQL Union templates: - src/datamodelcodegenerator/model/template/UnionTypeStatement.jinja2 - src/datamodelcodegenerator/model/template/UnionTypeAliasAnnotation.jinja2 - src/datamodelcodegenerator/model/template/UnionTypeAliasType.jinja2 Before 0.60.1, Union…

Published by the source

28 Jul 2026, 21:35 UTC

Last modified by the source

28 Jul 2026, 21:35 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-j884-q54q-mmx3

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# Patch Next advisory brief: CVE-2026-54621

Advisory: `datamodel-code-generator` vulnerable to code injection via unescaped carriage return in GraphQL Union description
IDs: CVE-2026-54621, GHSA-j884-q54q-mmx3
Record: https://patchnext.com/advisories/cve-2026-54621 (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 7.8)
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 0.60.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI datamodel-code-generator: affected >= 0.25.0, < 0.60.1; fixed in 0.60.1

## 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-j884-q54q-mmx3 (GitHub-reviewed advisory GHSA-j884-q54q-mmx3 lists affected ranges: PyPI datamodel-code-generator >=0.25.0 <0.60.1)

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