CVE-2026-31233: Guardrails ai Guardrails AI Contains A Code Vulnerability

CRITICAL
Advisory Identifier: GHSA-r6hf-g5x6-7pv9
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CVSS 9.8
CWE-94
Published
Advisory Summary

CVE-2026-31233 is a CRITICAL (CVSS 9.8) guardrails ai contains a code vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting Guardrails ai libraries in the PyPI ecosystem. The issue involves guardrails ai contains a code injection vulnerability in its hub package installation mechanism. Remediation is available in the latest vendor maintenance releases.

CVE-2026-31233 at a Glance

CVE Identifier CVE-2026-31233
GHSA Identifier GHSA-r6hf-g5x6-7pv9
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-94: Improper Control of Generation of Code ('Code Injection')
Affected Product Guardrails ai
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-31233

To remediate this vulnerability, upgrade all affected Guardrails ai dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

guardrails-ai fixed: Latest secure release 
pip install guardrails-ai>=Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show guardrails-ai

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-31233, inspect your installed packages using pip:

pip show guardrails-ai

Analyze the terminal output to locate any version of Guardrails ai in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The pip show guardrails-ai command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-94: Improper Control of Generation of Code ('Code Injection'), where the product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. In Guardrails ai, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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 post_install 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.

CVE-2026-31233 Affected Guardrails ai Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
guardrails-ai
pypi/guardrails-ai
PyPI
≤ 0.6.7

References

NVD — CVE-2026-31233 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-31233
Guardrails ai Source Repository REPOSITORY
https://github.com/guardrails-ai/guardrails
www.notion.so/cve-2026-31233-35d1... WEB
https://www.notion.so/CVE-2026-31233-35d1e13931888142a954fb3f50ee0c94

Frequently Asked Questions

What is CVE-2026-31233?
CVE-2026-31233 is a security vulnerability in Guardrails ai involving Guardrails AI contains a code injection vulnerability in its Hub package installation mechanism under CWE-94: Improper Control of Generation of Code ('Code Injection').
Which Guardrails ai versions are affected?
Affected versions include releases prior to current release patches across affected packages: guardrails-ai.
What version fixes CVE-2026-31233?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is guardrails-ai affected?
Yes, guardrails-ai is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-31233?
CVE-2026-31233 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-31233?
CVE-2026-31233 is classified under CWE-94: Improper Control of Generation of Code ('Code Injection') (The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.).
How can I check PyPI dependencies for CVE-2026-31233?
Run the dependency tree command: 'pip show guardrails-ai'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-r6hf-g5x6-7pv9",
  "modified" : "2026-05-27T22:03:04Z",
  "published" : "2026-05-12T18:30:40Z",
  "aliases" : [ "CVE-2026-31233" ],
  "summary" : "Guardrails AI contains a code injection vulnerability in its Hub package installation mechanism",
  "details" : "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 post_install 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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "guardrails-ai"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.6.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-31233"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/guardrails-ai/guardrails"
  }, {
    "type" : "WEB",
    "url" : "https://www.notion.so/CVE-2026-31233-35d1e13931888142a954fb3f50ee0c94"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-94" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-27T22:03:04Z",
    "nvd_published_at" : "2026-05-12T18:16:51Z"
  }
}