Bug 2566608 (CVE-2026-120640)

Summary: CVE-2026-120640 perl-cgi: perl-cgi: Request forgery via request body parameter spoofing
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in perl-cgi. This vulnerability allows a remote attacker to conduct request forgery by spoofing internal request body parameters through query strings or form fields. Because the module does not distinguish between actual request payloads and user-supplied parameters, an attacker can submit crafted input that the application mistakenly processes as a legitimate request body.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On: 2567293    
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Description OSIDB Bzimport 2026-11-03 23:52:19 UTC
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.