# CVE-2026-114651: Cross-document data leak via malformed BSON array parsing in reused thread buffer


- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/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-f8xm-c88f-wq46

## What is CVE-2026-114651?

CVE-2026-114651 is a medium-severity vulnerability in MongoDB C# Driver, published on 22 Oct 2026. 

### Official description

A memory-handling weakness in the BSON deserialization component of the MongoDB C# Driver may cause data left over from previously processed content to be returned when specially crafted serialized input is parsed. An unauthenticated party able to supply serialized data to an application that maps certain primitive collection types can cause residual bytes from unrelated data processed earlier on the same execution thread to be surfaced as legitimate values. This can result in disclosure of a limited amount of information belonging to other requests or principals of the consuming application. No authentication or special privileges within the application are required.

Weakness: CWE-908 (Use of Uninitialized Resource)

## Which versions are affected by CVE-2026-114651?


## How do I fix CVE-2026-114651?

No fix has been published for CVE-2026-114651 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-114651 being exploited?

There is no known exploitation of CVE-2026-114651 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-114651 and fix it if it is affected.

What it is: CVE-2026-114651 is a medium-severity vulnerability in MongoDB C# Driver, published on 22 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-114651 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-2026-114651/ (Markdown: https://insights.sbomify.com/CVE-2026-114651/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-114651
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-114651
- OSV: https://osv.dev/vulnerability/CVE-2026-114651

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-114651/
Summaries are generated and may contain mistakes; the official description above is the record.