CVE-2026-120639: vulnerability in CGI
CGI versions before 5.00 for Perl allow HTTP header injection via entity decoding after the newline check in header and unchecked values in multipart_start and do_push
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.2%
CGI versions before 5.00 for Perl allow HTTP header injection via entity decoding after the newline check in header and unchecked values in multipart_start and do_push.
With autoEscape off, header decodes HTML entities in extra header values after its newline check, so an encoded CR or LF reaches the response. multipart_start does not check header values for newlines, and do_push does not check the type it prints in each part.
An application that passes request data into these header values can be made to add headers or split the response.
Affected products
CGIRelated CVEs — CGI
In the same product, most dangerous first.
CVE-2026-120645—CGI versions before 5.00 for Perl allow denial of service via submitted values used as a regex for optgroup selection in scrolling_listEPSS 0.4%CVE-2026-120631—CGI::Cookie versions from 4.67 before 5.00 for Perl allow denial of service via the client cookie expires value used as a regex in parseEPSS 0.4%CVE-2026-120636—CGI versions before 5.00 for Perl allow open redirects and script injection via URLs built from REQUEST_URI in url and start_formEPSS 0.2%CVE-2026-120648—CGI versions before 5.00 for Perl allow HTML injection via text containing --> in commentEPSS 0.2%CVE-2026-120643—CGI versions from 4.62 before 5.00 for Perl allow cross-site scripting via a raw apostrophe in URLs returned by url and self_urlEPSS 0.2%CVE-2026-120647—CGI versions before 5.00 for Perl allow Content-Disposition parameter injection via unescaped double quotes in the header attachment filenameEPSS 0.2%