Is this vulnerability remotely exploitable?

Yes. If an application exposes HTTP endpoints that accept ormar models as JSON request bodies, a remote attacker who can send crafted requests to those endpoints can attempt to exploit the issue over the network.

Does an attacker need authentication to exploit this?

Not necessarily. If affected endpoints are publicly accessible and do not enforce authentication, any unauthenticated user can send payloads including `__pk_only__` or `__excluded__`. If access is restricted, the vulnerability is limited to authenticated users who can reach those routes.

What is the safest general fix pattern?

The most robust pattern is to stop using ormar `Model` classes directly as API request schemas. Instead, define separate Pydantic request models, validate all incoming data against those, and then explicitly construct ormar models from validated fields. This design prevents internal ORM flags from being supplied by clients.

Severity:

HIGH RISK

(7.1)

Validation Bypass via Hidden Control Fields (CWE-20) in ormar FastAPI Models

CVE-2026-27953

Published:

Mar 19, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

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May 6, 2026

Vulnerability Type

Category:

Input Validation Bypass

CWE:

CWE-20;CWE-915

Impact:

Authorization and Data Integrity Compromise

Severity:

HIGH RISK

(7.1)

CVSS Version:

3.1

Vulnerability Type

Category:

Input Validation Bypass

CWE:

CWE-20;CWE-915

Impact:

Authorization and Data Integrity Compromise

Severity:

HIGH RISK

(7.1)

CVSS Version:

3.1

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Validation Bypass via Hidden Control Fields (CWE-20) in ormar FastAPI Models

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(8.6)

Server-Side Request Forgery (CWE-918) in OpenClaw Zalo Plugin sendPhoto

HIGH RISK

HIGH

(8.8)

Authorization Bypass (CWE-863) in OpenClaw Matrix Room Control Commands

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

Ship clean & secure code faster

Ship clean & secure code faster

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