CVE-2026-120640
UnratedPublished 2026-11-04 ยท last changed 2026-11-04
The fix
We hold no Microsoft remediation data for CVE-2026-120640, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.
What it is
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.