Prototype Pollution in Ajv.js Ajv

CVE-2020-15366

An issue was discovered in ajv.validate() in Ajv (aka Another JSON Schema Validator) 6.12.2. A carefully crafted JSON schema could be provided that allows execution of other code by prototype pollution. (While untrusted schemas are recommended against, the worst case of an untrusted schema should be a denial of service, not execution of code.)

Vulnerability class: Prototype Pollution

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.023 (82.7th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 83rd percentile — 82.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2020-15366: held from 0.023 to 0.023.

EPSS over last 30 days · oldest: 0.023 · newest: 0.023 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-15366?
CVE-2020-15366 is a medium-severity vulnerability in Ajv.js Ajv, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 5.6/10. Published 2020-07-15.
How severe is CVE-2020-15366?
Medium severity. CVSS v3 base score is 5.6 out of 10.
Is CVE-2020-15366 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.