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.
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.
Metrics
Affected Vendors & Products
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Advisories
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Fixes
Solution
Upgrade to CGI 5.00 or later.
Workaround
For deployments that cannot upgrade, check the request Content-Type before trusting param('POSTDATA').
References
History
Wed, 04 Nov 2026 00:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| 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 | |
| Weaknesses | CWE-352 | |
| References |
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Projects
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MITRE
Status: PUBLISHED
Assigner: CPANSec
Published:
Updated: 2026-11-03T23:40:33.770Z
Reserved: 2026-11-02T17:41:07.710Z
Link: CVE-2026-120640
Vulnrichment
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NVD
Status : Received
Published: 2026-11-04T00:17:25.390
Modified: 2026-11-04T00:17:25.390
Link: CVE-2026-120640
Redhat
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OpenCVE Enrichment
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Weaknesses