# CVE-2026-114647: NoSQL operator injection via unvalidated replacement document in findOneAndReplace


- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 22 Oct 2026
- **Updated:** 22 Oct 2026
- **Also known as:** GHSA-68cj-624m-mxj3

## What is CVE-2026-114647?

CVE-2026-114647 is a medium-severity vulnerability in MongoDB C# Driver, published on 22 Oct 2026. 

### Official description

The MongoDB C# Driver does not reject replacement documents whose top-level field names begin with a dollar sign in FindOneAndReplace, unlike other replace operations. An application that builds such a document from user-supplied field names can have the server apply update operators instead of a full replacement. The effect is limited to the document matched by the application's own filter, whose contents can be modified in ways the application did not intend.

Weakness: CWE-943 (Improper Neutralization of Special Elements in Data Query Logic)

## Which versions are affected by CVE-2026-114647?


## How do I fix CVE-2026-114647?

No fix has been published for CVE-2026-114647 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-114647 being exploited?

There is no known exploitation of CVE-2026-114647 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-114647 and fix it if it is affected.

What it is: CVE-2026-114647 is a medium-severity vulnerability in MongoDB C# Driver, published on 22 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-114647 in the wild and no public exploit code.

Affected product: MongoDB C# Driver. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-114647/ (Markdown: https://insights.sbomify.com/CVE-2026-114647/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-114647
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-114647
- OSV: https://osv.dev/vulnerability/CVE-2026-114647

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-114647/
Summaries are generated and may contain mistakes; the official description above is the record.