CVE-2026-73562: Mongoose prototype pollution via __proto__ in update casting

CVE-2026-73562 · Severity: medium · CVSS 6.5 · Published 2026-08-13

Mongoose is a popular Node.js library for working with MongoDB databases. A prototype pollution vulnerability allows attackers to inject malicious properties into JavaScript's Object.prototype by passing specially crafted update objects to Mongoose queries like updateOne(). This can lead to data integrity issues and potential application malfunction across the entire process.

Technologies: mongoose (npm). Vendors: npm.

Quick answers

Is CVE-2026-73562 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-73562 being exploited in the wild.
How severe is CVE-2026-73562?
Medium severity, with a CVSS score of 6.5, published 13 August 2026.
Which products and versions are affected?
mongoose (npm) SEMVER:introduced=0,fixed=6.13.10.
Is there a fix for CVE-2026-73562?
Yes. mongoose (npm): upgrade to 6.13.10 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-73562 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-73562?
Check whether you run mongoose (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • mongoose (npm): upgrade to 6.13.10 or later
    npm install mongoose@6.13.10

Technical details

The vulnerability is a prototype pollution (CWE-1321) in Mongoose's update casting logic. When processing user-controlled updates containing __proto__-prefixed dotted paths (e.g., "__proto__.x"), the Schema._getSchema/path getter fails to properly sanitize the input, causing Mongoose to set properties like $fullPath and $parentSchemaDocArray directly on Object.prototype. Attack vector is network-based with no authentication or user interaction required; any application accepting user input in update operations (e.g., MyModel.updateOne(filter, req.body)) is vulnerable. The pollution persists across the application runtime, affecting all subsequently created objects. Patches are available in versions 6.13.10, 7.8.10, 8.24.1, and 9.7.2.

Affected products

  • Automattic Mongoose <6.13.10, 7.0.0-7.8.9, 8.0.0-8.24.0, 9.0.0-9.7.1

Identifiers

  • CVE-2026-73562
  • GHSA-664h-wqgq-64gw

Timeline

  • 2026-07-24: disclosed
  • 2026-07-24: patched: Patches released: 6.13.10, 7.8.10, 8.24.1, 9.7.2

References

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