CVE-2026-125117 Mongoose walks into inherited properties when hydrating, setting, and merging, allowing overwrites of built-in functions (denial of service) and shared schema state
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-125117?
CVE-2026-125117 is a high-severity vulnerability in Automattic mongoose, published on 9 Nov 2026.
Official description
Mongoose is a MongoDB object modeling tool designed to work in an asynchronous environment. Prior to 6.13.12, 7.8.13, 8.24.7, and 9.11.4, Mongoose can descend into inherited properties while loading database documents in init(), setting dotted paths in $__set, and merging update documents in utils.mergeClone. Attacker-controlled keys such as toString or valueOf can therefore cause Mongoose to write into shared built-in functions instead of an own property. A crafted document, Mixed path, non-strict document or subdocument, findOneAndReplace() replacement, chained update, or Query.prototype.merge() source can overwrite Object.prototype.toString.call, causing later queries on unrelated models to fail until the process restarts. Separately, when an attacker controls the dotted path passed to doc.set(path, value) for a subdocument configured with strict: false, descent through $__set can reach $__schema and alter shared validators or schema options for later documents. Mongoose already blocks __proto__, constructor, and prototype, so this issue overwrites properties on reachable shared objects rather than adding new properties directly to Object.prototype. This issue is fixed in versions 6.13.12, 7.8.13, 8.24.7, and 9.11.4.
Weakness: CWE-1321
Which versions are affected by CVE-2026-125117?
4 open source packages ship an affected version, including mongoose.
| Package | Affected | Fixed in |
|---|---|---|
mongoose npm | All versions | 6.13.12 |
mongoose npm | From 7.0.0 | 7.8.13 |
mongoose npm | From 8.0.0 | 8.24.7 |
mongoose npm | From 9.0.0 | 9.11.4 |
How do I fix CVE-2026-125117?
Upgrade mongoose to a fixed version for your release line: 6.13.12, 7.8.13, 8.24.7 or 9.11.4.
Is CVE-2026-125117 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-125117 exists.
Sources
Also known as GHSA-8332-j7wj-wjw4.