# CVE-2026-44723: Command injection in vowpal wabbit

> Attackers can execute arbitrary commands on CI runners by crafting malicious pull request titles in Vowpal Wabbit's GitHub Actions workflow.

- **Severity:** Medium 5.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 May 2026
- **Updated:** 28 May 2026
- **Also known as:** GHSA-cg2g-xgg7-3xxq

## What is CVE-2026-44723?

CVE-2026-44723 is a medium-severity command injection vulnerability in VowpalWabbit vowpal_wabbit, published on 26 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Vowpal Wabbit is a machine learning system. The workflow .github/workflows/python_checks.yml embeds ${{ github.event.pull_request.title }} directly inside double-quoted bash strings in four separate steps across four jobs, each passing it as a CLI argument to the Python test script run_tests_model_gen_and_load.py. The shell interprets the expanded string before invoking Python, allowing an attacker to break out of the quotes and execute arbitrary commands on the runner. The pull_request trigger fires on PRs targeting any branch (branches: ['*']), with no additional access gate. This vulnerability is fixed by the 998e390e80a7e8192d7849b7784bc113dbd190ad commit.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command), CWE-1336 (Improper Neutralization of Special Elements Used in a Template Engine)

## Which versions are affected by CVE-2026-44723?

It affects 1 product.


Products: Vowpalwabbit Vowpal Wabbit.

## How do I fix CVE-2026-44723?

No fix has been published for CVE-2026-44723 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-44723 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44723 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-44723 and fix it if it is affected.

What it is: CVE-2026-44723 is a medium-severity command injection vulnerability in VowpalWabbit vowpal_wabbit, published on 26 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44723 exists.

Affected product: VowpalWabbit vowpal_wabbit. 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-2026-44723/ (Markdown: https://insights.sbomify.com/CVE-2026-44723/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-44723
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-44723
- OSV: https://osv.dev/vulnerability/CVE-2026-44723

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-44723/
Summaries are generated and may contain mistakes; the official description above is the record.