---
title: "CVE-2026-31233: Guardrails AI contains a code injection vulnerability in its Hub package installation mechanism"
url: https://erroneo.us/security/cve/CVE-2026-31233/
description: "CVE-2026-31233 (guardrails-ai (PyPI)): Guardrails AI thru 0.6.7 contains a code injection vulnerability (CWE-94) in its Hub package installation mechanism.…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-05-12
date_modified: 2026-05-27
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-31233"
kev: false
cvss: 9.8
epss: 0.00926
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-31233: Guardrails AI contains a code injection vulnerability in its Hub package installation mechanism

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.9% , percentile 60: FIRST’s model estimates a 0.9% chance of exploitation activity in the next 30 days, higher than 60% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes guardrails-ai (PyPI) <= 0.6.7, no fixed version listed . Check your lockfile, including transitive dependencies.

## What it is

Guardrails AI thru 0.6.7 contains a code injection vulnerability (CWE-94) in its Hub package installation mechanism. When installing validator packages via guardrails hub install, the system retrieves a manifest from the Guardrails Hub and dynamically executes a script specified in the postinstall field. The script path is constructed from untrusted manifest data and executed without proper validation or sanitization, allowing remote code execution. An attacker who can publish malicious packages to the Hub can inject arbitrary code that will be executed on any system where a victim installs the malicious package.

## Affected packages

- PyPI `guardrails-ai` <= 0.6.7 → fixed: none listed

## Affected products (CVE record)

- n/a n/a: see advisory

## Severity

- CISA-ADP CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.93% probability of exploitation activity in the next 30 days; percentile 60.

## Sources

- [GitHub Advisory GHSA-r6hf-g5x6-7pv9](https://github.com/advisories/GHSA-r6hf-g5x6-7pv9)
- [CVE.org record CVE-2026-31233](https://www.cve.org/CVERecord?id=CVE-2026-31233)
- [NVD entry CVE-2026-31233](https://nvd.nist.gov/vuln/detail/CVE-2026-31233)
- [github.com](https://github.com/guardrails-ai/guardrails)
- [notion.so](https://www.notion.so/CVE-2026-31233-35d1e13931888142a954fb3f50ee0c94)

---
Source page: https://erroneo.us/security/cve/CVE-2026-31233/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt