# CVE-2023-0437: MongoDB client C Driver may infinitely loop when validating certain BSON input data

> An attacker can cause a denial of service by sending specific BSON data that triggers an infinite loop in the MongoDB C Driver's UTF-8 validation.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Jan 2024
- **Updated:** 3 Nov 2025
- **Also known as:** DEBIAN-CVE-2023-0437, GHSA-8549-4c5j-x7g2, JLSEC-2026-179, OESA-2024-1076

## What is CVE-2023-0437?

CVE-2023-0437 is a medium-severity denial of service vulnerability in MongoDB C Driver, published on 12 Jan 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

When calling bson_utf8_validate on some inputs a loop with an exit condition that cannot be reached may occur, i.e. an infinite loop. This issue affects All MongoDB C Driver versions prior to versions 1.25.0.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2023-0437?

It affects 1 product.


Products: Mongodb C Driver.

## How do I fix CVE-2023-0437?

Upgrade to a fixed version.

## Is CVE-2023-0437 being exploited?

There is no known exploitation of CVE-2023-0437 in the wild and no public exploit code.

## Other vulnerabilities in MongoDB C Driver

- [CVE-2026-93393](https://insights.sbomify.com/CVE-2026-93393/): Heap overflow via oversized decrypted TLS record sequence in Windows Secure Channel stream (critical 9.2)
- [CVE-2026-6691](https://insights.sbomify.com/CVE-2026-6691/): MongoDB C Driver Cyrus SASL Canonicalization Buffer Overflow (high 8.6)
- [CVE-2026-84964](https://insights.sbomify.com/CVE-2026-84964/): Heap corruption via OCSP request double free from crafted multi-URL certificate in TLS client (high 8.2)
- [CVE-2024-7553](https://insights.sbomify.com/CVE-2024-7553/): Accessing Untrusted Directory May Allow Local Privilege Escalation (high 7.3)
- [CVE-2026-93395](https://insights.sbomify.com/CVE-2026-93395/): Integer Underflow → Heap Out-of-Bounds Read in `bson_new_from_buffer() (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-0437 and fix it if it is affected.

What it is: CVE-2023-0437 is a medium-severity denial of service vulnerability in MongoDB C Driver, published on 12 Jan 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-0437 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-2023-0437/ (Markdown: https://insights.sbomify.com/CVE-2023-0437/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-0437
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-0437
- OSV: https://osv.dev/vulnerability/CVE-2023-0437

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-0437/
Summaries are generated and may contain mistakes; the official description above is the record.