Vulnerability · Published Nov 3, 2026 · Assigned by CPANSec
CVE-2026-120640CGI 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
Unrated
In plain English
A cross-site request forgery in CGI. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities).
Official description
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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120640 |
| Debian:13 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120640 |
| Debian:14 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120640 |
| Ubuntu:22.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120640 |
| Ubuntu:24.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120640 |
| Ubuntu:26.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120640 |
| Ubuntu:26.10 | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120640 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| CGI | 0 – before 5.00 |
Weakness: CWE-352