# CVE-2020-37167: ClamAV ClamBC < 0.103.0-rc - 'ClamBC' Executable Regular Expression Error

> Attackers can exploit weak input validation in ClamAV bytecode interpreter to execute malicious bytecode or cause unexpected behavior.

- **Severity:** High 8.6 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Feb 2026
- **Updated:** 30 Sep 2026
- **Also known as:** DEBIAN-CVE-2020-37167, GHSA-9wpq-3w4j-985q

## What is CVE-2020-37167?

CVE-2020-37167 is a high-severity code injection vulnerability in ClamAV ClamBC, published on 12 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

ClamAV versions prior to 0.103.0-rc contain a vulnerability in function name processing through the ClamBC bytecode interpreter that allows attackers to manipulate bytecode function names. Attackers can exploit the weak input validation in function name encoding to potentially execute malicious bytecode or cause unexpected behavior in the ClamAV engine.

## Which versions are affected by CVE-2020-37167?


## How do I fix CVE-2020-37167?

Upgrade to a fixed version.

## Is CVE-2020-37167 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-37167 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-37167 and fix it if it is affected.

What it is: CVE-2020-37167 is a high-severity code injection vulnerability in ClamAV ClamBC, published on 12 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-37167 exists.

Affected product: ClamAV ClamBC. 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-2020-37167/ (Markdown: https://insights.sbomify.com/CVE-2020-37167/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-37167
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-37167
- OSV: https://osv.dev/vulnerability/CVE-2020-37167

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-37167/
Summaries are generated and may contain mistakes; the official description above is the record.