# CVE-2026-31236: llm CLI tool contains a code injection vulnerability via `--functions` command-line argument

> Attackers can execute arbitrary Python code via the --functions argument in the llm CLI tool, requiring social engineering to trick victims into running malicious commands.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 May 2026
- **Updated:** 15 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-31236, GHSA-g76p-4vg5-f4qh, PYSEC-2026-400, UBUNTU-CVE-2026-31236

## What is CVE-2026-31236?

CVE-2026-31236 is a critical code injection vulnerability in n/a, published on 12 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The llm CLI tool thru 0.27.1 contains a critical code injection vulnerability via its --functions command-line argument. This argument is intended to allow users to provide custom Python function definitions. However, the tool directly executes the provided code using the unsafe exec() function without any sanitization, sandboxing, or security restrictions. An attacker can exploit this by crafting a malicious llm command with arbitrary Python code in the --functions argument and using social engineering to trick a victim into running it. This leads to arbitrary code execution on the victim's system, potentially granting the attacker full control.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-31236?

3 open source packages ship an affected version, including llm.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `llm` | PyPI | All versions to 0.27.1 | None |
| `llm` | PyPI | All versions to 0.27.1 | None |
| `llm` | PyPI | All versions to 0.27.1 | None |

## How do I fix CVE-2026-31236?

No fix has been published for CVE-2026-31236 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-31236 being exploited?

There is no known exploitation of CVE-2026-31236 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-31236 and fix it if it is affected.

What it is: CVE-2026-31236 is a critical code injection vulnerability in n/a, published on 12 May 2026. 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-2026-31236 in the wild and no public exploit code.

Affected packages and fixed versions:
- llm (PyPI): affected all versions up to 0.27.1; no fix listed
- llm (PyPI): affected all versions up to 0.27.1; no fix listed
- llm (PyPI): affected all versions up to 0.27.1; no fix listed

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-2026-31236/ (Markdown: https://insights.sbomify.com/CVE-2026-31236/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31236
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31236
- OSV: https://osv.dev/vulnerability/CVE-2026-31236

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31236/
Summaries are generated and may contain mistakes; the official description above is the record.