---
id: "CVE-2026-120637"
kind: "vulnerability"
aliases: ["CVE-2026-120637"]
title: "Perl CGI module reads request parameters from command line arguments"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["cgi", "package", "perl", "self-hosted"]
not_affected_if: ["no-perl-cgi", "static-site"]
published_at: "2026-11-04T00:17:24+00:00"
first_seen_at: "2026-11-04T00:46:16+00:00"
updated_at: "2026-11-04T00:48:19+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-120637", "first_seen_at": "2026-11-04T00:46:16+00:00"}]
---

# Perl CGI module reads request parameters from command line arguments

CGI versions before 5.00 for Perl, when given an unrecognised REQUEST_METHOD such as OPTIONS, fall back to offline debugging mode and build request parameters from the process command line. The sources do not state a direct attacker impact beyond that parameter source being wrong.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed CGI module version with `perl -MCGI -e 'print $CGI::VERSION'`
- Confirm whether a web application uses the CGI module for request handling

## Fix

- Move to CGI `5.00` or later, per the linked patch

## Timeline

- 2026-11-04T00:46:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-120637

## Documents

- [fix] Patch: github.com https://github.com/leejo/CGI.pm/commit/b753ff75a3bc4554c075cc37c1db605a55297029.patch

## From the sources

CGI versions before 5.00 for Perl take request parameters from the process command line arguments for an unrecognised REQUEST_METHOD.

For a REQUEST_METHOD such as OPTIONS, CGI falls through to its offline debugging mode, which is on by default, and builds the parameters and path_info from the process's command line arguments.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_