---
id: CVE-2026-120640
title: >-
  CGI versions before 5.00 for Perl allow the POSTDATA, PUTDATA, PATCHDATA and
  XForms:Model parameters to be set from the query string or form fields
summary: >-
  CGI versions before 5.00 for Perl allow the POSTDATA, PUTDATA, PATCHDATA and
  XForms:Model parameters to be set from the query string or form fields.


  CGI stores a non-form request body under POSTDATA, PUTDATA or PATCHDATA, and
  an XForms …
severity: none
cwe:
  - CWE-352
product: CGI
affected:
  - CGI < 5.00
published: '2026-11-03'
updated: '2026-11-03'
sourceUpdated: '2026-11-03T23:40:33.770Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-120640'
references:
  - url: 'https://metacpan.org/release/LEEJO/CGI-4.72/source/lib/CGI.pm'
  - url: 'https://metacpan.org/release/LEEJO/CGI-5.00/changes'
  - url: >-
      https://github.com/leejo/CGI.pm/commit/bc4022f553301014e522133ba1e1f4e49e3bef08.patch
tags:
  - cve.org
epss: 0.00131
epssPercentile: 0.02694
ingestedAt: '2026-11-05T20:33:06.620Z'
---

## Overview

CGI versions before 5.00 for Perl allow the POSTDATA, PUTDATA, PATCHDATA and XForms:Model parameters to be set from the query string or form fields.

CGI stores a non-form request body under POSTDATA, PUTDATA or PATCHDATA, and an XForms body under XForms:Model, but also accepts these names from the query string, a form field or a multipart part, so an application cannot tell a client-sent value from the real body.

A cross-site HTML form can post POSTDATA={"admin":true} to an endpoint that reads JSON from param('POSTDATA'), a request forgery that needs no CORS preflight.

## Affected

- `CGI < 5.00`

## Remediation

Upgrade to CGI 5.00 or later.

### Workarounds

For deployments that cannot upgrade, check the request Content-Type before trusting param('POSTDATA').