CVE-2026-27953
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of data tampering.
- Exploit odds
- 1.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.2% in the next 30 days (EPSS).
- Severity: 7.1 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.2% · EPSS, next 30 days
- Weakness
- CWE-20 · Improper input validation
- Record status
- Analyzed
Affected
- Collerek Ormar < 0.23.1
Attack profile CVSS 3.1 · 7.1
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- Low
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-27953.md and follow it. Check whether this project is affected by CVE-2026-27953. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/ormar-orm/ormar/blob/master/examples/fastapi_quick_start.py#L55
- https://github.com/ormar-orm/ormar/blob/master/ormar/fields/foreign_key.py#L41
- https://github.com/ormar-orm/ormar/blob/master/ormar/models/helpers/pydantic.py#L108
- https://github.com/ormar-orm/ormar/blob/master/ormar/models/model.py#L89
- https://github.com/ormar-orm/ormar/blob/master/ormar/models/newbasemodel.py#L128
- https://github.com/ormar-orm/ormar/blob/master/ormar/models/newbasemodel.py#L292
- https://github.com/ormar-orm/ormar/commit/7f22aa21a7614b993970345b392dabb0ccde0ab3
- https://github.com/ormar-orm/ormar/releases/tag/0.23.1
- https://github.com/ormar-orm/ormar/security/advisories/GHSA-f964-whrq-44h8
- https://github.com/ormar-orm/ormar/security/advisories/GHSA-f964-whrq-44h8
References
- https://github.com/ormar-orm/ormar/blob/master/examples/fastapi_quick_start.py#L55
- https://github.com/ormar-orm/ormar/blob/master/ormar/fields/foreign_key.py#L41
- https://github.com/ormar-orm/ormar/blob/master/ormar/models/helpers/pydantic.py#L108
- https://github.com/ormar-orm/ormar/blob/master/ormar/models/model.py#L89
- https://github.com/ormar-orm/ormar/blob/master/ormar/models/newbasemodel.py#L128
- https://github.com/ormar-orm/ormar/blob/master/ormar/models/newbasemodel.py#L292
- https://github.com/ormar-orm/ormar/commit/7f22aa21a7614b993970345b392dabb0ccde0ab3
- https://github.com/ormar-orm/ormar/releases/tag/0.23.1
- https://github.com/ormar-orm/ormar/security/advisories/GHSA-f964-whrq-44h8
- https://github.com/ormar-orm/ormar/security/advisories/GHSA-f964-whrq-44h8