Access of Resource Using Incompatible Type ('Type Confusion') Affecting mongoose package, versions <6.13.12>=7.0.0 <7.8.13>=8.0.0 <8.24.7>=9.0.0 <9.11.4
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published11 Nov 2026
- disclosed10 Nov 2026
- creditUnknown
Introduced: 10 Nov 2026
NewCVE-2026-125116 (opens in a new tab)How to fix?
Upgrade mongoose to version 6.13.12, 7.8.13, 8.24.7, 9.11.4 or higher.
Overview
mongoose is a Mongoose is a MongoDB object modeling tool designed to work in an asynchronous environment.
Affected versions of this package are vulnerable to Access of Resource Using Incompatible Type ('Type Confusion') via the discriminator key lookup in getDiscriminatorByKey and related code paths, when a user-controlled discriminator key value (e.g. __t: 'constructor') is used to index a plain-object discriminator registry (Model.discriminators[doc.__t]) without an own-property check. Because the registry is a plain object, inherited Object.prototype properties such as constructor, toString, and hasOwnProperty resolve to built-in functions instead of discriminator models. This causes a TypeError or returns a raw object where a Mongoose document is expected, crashing the affected request. Through bulkWrite() insertOne with skipValidation: true, the raw user object is stored without schema casting or strict filtering, and every subsequent query returning that document throws until it is manually removed from the database.
Note: The persistent denial of service and schema bypass require the application to call bulkWrite() with skipValidation: true on untrusted input.