ormar is a async mini ORM for Python. Versions 0.23.0 and below are vulnerable to Pydantic validation bypass through the model constructor, allowing any unauthenticated user to skip all field validation by injecting "__pk_only__": true into a JSON request body. By injecting "__pk_only__": true into a JSON request body, an unauthenticated attacker can skip all field validation and persist unvalidated data directly to the database. A secondary __excluded__ parameter injection uses the same pattern to selectively nullify arbitrary model fields (e.g., email or role) during construction. This affects ormar's canonical FastAPI integration pattern recommended in its official documentation, enabling privilege escalation, data integrity violations, and business logic bypass in any application using ormar.Model directly as a request body parameter. This issue has been fixed in version 0.23.1.
Metrics
Affected Vendors & Products
Advisories
| Source | ID | Title |
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Github GHSA |
GHSA-f964-whrq-44h8 | ormar Pydantic Validation Bypass via __pk_only__ and __excluded__ Kwargs Injection in Model Constructor |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 19 Mar 2026 20:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | ormar is a async mini ORM for Python. Versions 0.23.0 and below are vulnerable to Pydantic validation bypass through the model constructor, allowing any unauthenticated user to skip all field validation by injecting "__pk_only__": true into a JSON request body. By injecting "__pk_only__": true into a JSON request body, an unauthenticated attacker can skip all field validation and persist unvalidated data directly to the database. A secondary __excluded__ parameter injection uses the same pattern to selectively nullify arbitrary model fields (e.g., email or role) during construction. This affects ormar's canonical FastAPI integration pattern recommended in its official documentation, enabling privilege escalation, data integrity violations, and business logic bypass in any application using ormar.Model directly as a request body parameter. This issue has been fixed in version 0.23.1. | |
| Title | ormar has a Pydantic Validation Bypass via Kwargs Injection in Model Constructor | |
| Weaknesses | CWE-20 CWE-915 |
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| References |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-03-19T20:23:06.379Z
Reserved: 2026-02-25T03:11:36.691Z
Link: CVE-2026-27953
No data.
Status : Received
Published: 2026-03-19T21:17:09.573
Modified: 2026-03-19T21:17:09.573
Link: CVE-2026-27953
No data.
OpenCVE Enrichment
No data.
Github GHSA