llm CLI tool contains a code injection vulnerability via --functions command-line argument

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-31236: 0.33% estimated exploitation activity in the next 30 days; percentile 25.83 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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.

Published by the source

12 May 2026, 18:30 UTC

Last modified by the source

29 Jun 2026, 12:26 UTC

Source last checked

26 Oct 2026, 13:41 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-g76p-4vg5-f4qh

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-g76p-4vg5-f4qh

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-g76p-4vg5-f4qh

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# Patch Next advisory brief: CVE-2026-31236

Advisory: llm CLI tool contains a code injection vulnerability via `--functions` command-line argument
IDs: CVE-2026-31236, GHSA-g76p-4vg5-f4qh
Record: https://patchnext.com/advisories/cve-2026-31236 (revision 3, source checked 26 Oct 2026, 13:41 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI llm: affected <= 0.27.1

## Suggested inspection (read-only)
- `python -m pip show llm`: prints the installed version. Run with the environment that serves production active.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on llm.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-g76p-4vg5-f4qh (GitHub-reviewed advisory GHSA-g76p-4vg5-f4qh lists affected ranges: PyPI llm >=0 <=0.27.1)
- Verified: https://osv.dev/vulnerability/GHSA-g76p-4vg5-f4qh (OSV record GHSA-g76p-4vg5-f4qh lists affected ranges: PyPI llm >=0 <=0.27.1)

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