# CVE-2020-12135: Integer overflow in n/a

> An integer overflow in the bson library allows attackers to cause denial of service or potentially execute code via crafted input.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 24 Apr 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-12135, GHSA-f54q-h8mw-5h8w, UBUNTU-CVE-2020-12135

## What is CVE-2020-12135?

CVE-2020-12135 is a medium-severity vulnerability in n/a, published on 24 Apr 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

bson before 0.8 incorrectly uses int rather than size_t for many variables, parameters, and return values. In particular, the bson_ensure_space() parameter bytesNeeded could have an integer overflow via properly constructed bson input.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2020-12135?

It affects 2 products.


Products: Mongodb C Driver, Whoopsie Project Whoopsie.

## How do I fix CVE-2020-12135?

Upgrade to a fixed version.

## Is CVE-2020-12135 being exploited?

There is no known exploitation of CVE-2020-12135 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [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-2020-12135 and fix it if it is affected.

What it is: CVE-2020-12135 is a medium-severity vulnerability in n/a, published on 24 Apr 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-12135 in the wild and no public exploit code.

Affected product: n/a. 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-2020-12135/ (Markdown: https://insights.sbomify.com/CVE-2020-12135/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-12135
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-12135
- OSV: https://osv.dev/vulnerability/CVE-2020-12135

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-12135/
Summaries are generated and may contain mistakes; the official description above is the record.