title: Prototype Pollution
description: This affects all versions of package mout. The deepFillIn function can be used to 'fill missing properties recursively', while the deepMixIn mixes objects into the target object, recursively mixing existing child objects as well. In both cases, the key used to access the target object recursively is not checked, leading to exploiting this vulnerability. **Note:** This vulnerability derives from an incomplete fix of [CVE-2020-7792](https://security.snyk.io/vuln/SNYK-JS-MOUT-1014544).
problem types: Prototype Pollution
affected:
{
product: mout
vendor: n/a
versions:
lessThan: unspecified, status: affected, version: 0, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
confidentialityImpact: NONE
exploitCodeMaturity: PROOF_OF_CONCEPT
integrityImpact: NONE
privilegesRequired: NONE
remediationLevel: NOT_DEFINED
reportConfidence: NOT_DEFINED
scope: UNCHANGED
temporalScore: 7.1
temporalSeverity: HIGH
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P
version: 3.1
]