CVE-2020-7766: Prototype Pollution

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.9% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-11-10 · updated 2026-06-17
Weakness: CWE-1321

Description

This affects all versions of package json-ptr. The issue occurs in the set operation (https://flitbit.github.io/json-ptr/classes/_src_pointer_.jsonpointer.htmlset) when the force flag is set to true. The function recursively set the property in the target object, however it does not properly check the key being set, leading to a prototype pollution.

Affected products

json-ptr: before 2.0.0 — fixed in 2.0.0

How to fix

Upgrade to a fixed version: json-ptr 2.0.0. Check the vendor advisory for mitigations.

References

https://github.com/flitbit/json-ptr/blob/master/src/util.ts%23L174
https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1038396
https://snyk.io/vuln/SNYK-JS-JSONPTR-1016939
https://github.com/flitbit/json-ptr/blob/master/src/util.ts%23L174
https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1038396
https://snyk.io/vuln/SNYK-JS-JSONPTR-1016939

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