Improper input validation in Collerek Ormar
CVE-2026-27953
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.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L.
EPSS exploit prediction
EPSS: 0.009 (58.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.009 · change: -0.003
Affected products
- Collerek Ormar
- Ormar-Orm Ormar — versions < 0.23.1
Weakness classification (CWE)
References
- github.com/ormar-orm/ormar/security/advisories/GHSA-f964-whrq-44h8 (Exploit, Mitigation, Vendor Advisory)
- github.com/ormar-orm/ormar/commit/7f22aa21a7614b993970345b392dabb0ccde0ab3 (Patch)
- github.com/ormar-orm/ormar/blob/master/examples/fastapi_quick_start.py (Patch)
- github.com/ormar-orm/ormar/blob/master/ormar/fields/foreign_key.py (Patch)
- github.com/ormar-orm/ormar/blob/master/ormar/models/helpers/pydantic.py (Patch)
- github.com/ormar-orm/ormar/blob/master/ormar/models/model.py (Patch)
- github.com/ormar-orm/ormar/blob/master/ormar/models/newbasemodel.py (Patch)
- github.com/ormar-orm/ormar/blob/master/ormar/models/newbasemodel.py (Patch)
- github.com/ormar-orm/ormar/releases/tag/0.23.1 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-27953?
- CVE-2026-27953 is a high-severity vulnerability in Collerek Ormar, classified under Improper Input Validation. CVSS score: 7.1/10. Published 2026-03-19.
- How severe is CVE-2026-27953?
- High severity. CVSS v3 base score is 7.1 out of 10.