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Vulnerability · Published Nov 3, 2026 · Assigned by CPANSec

CVE-2026-120636CGI versions before 5.00 for Perl allow open redirects and script injection via URLs built from REQUEST_URI in url and start_form

Unrated

In plain English

A open redirect in CGI. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities).

Severity (CVSS )–Not rated
Exploit odds (30 days)0.2%top 88.4% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

CGI versions before 5.00 for Perl allow open redirects and script injection via URLs built from REQUEST_URI in url and start_form. url(-absolute=>1), url(-relative=>1) and the default start_form action are built from the client-supplied REQUEST_URI without validation. The result can be protocol-relative (//evil.example), absolute-form (http://evil.example/) or contain backslashes, and url(-relative=>1) can return a javascript: URL. Links and form posts built from these URLs can go to another host.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12libcgi-pm-perlno fix listedDEBIAN-CVE-2026-120636
Debian:13libcgi-pm-perlno fix listedDEBIAN-CVE-2026-120636
Debian:14libcgi-pm-perlno fix listedDEBIAN-CVE-2026-120636
Ubuntu:22.04:LTSlibcgi-pm-perlno fix listedUBUNTU-CVE-2026-120636
Ubuntu:24.04:LTSlibcgi-pm-perlno fix listedUBUNTU-CVE-2026-120636
Ubuntu:26.04:LTSlibcgi-pm-perlno fix listedUBUNTU-CVE-2026-120636
Ubuntu:26.10libcgi-pm-perlno fix listedUBUNTU-CVE-2026-120636

Affected products (as reported)

VendorProductVersions
CGI 0 – before 5.00

Weakness: CWE-601, CWE-79

References