Description
CGI versions before 5.00 for Perl allow open redirects via HTML entity decoding of the URL after application validation in redirect.
redirect decodes HTML entities in its URL before writing the Location header, so a URL the application has already validated can change meaning. For example, //evil.example/ becomes //evil.example/ and sends the user to another host.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | CGI | < 5.00 | 5.00 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libcgi-pm-perl | No fix yet | — |
| Debian 13 | libcgi-pm-perl | No fix yet | — |
| Debian 12 | libcgi-pm-perl | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libcgi-pm-perl | No fix yet | — |
| Ubuntu 26.04 LTS | libcgi-pm-perl | No fix yet | — |
| Ubuntu 24.04 LTS | libcgi-pm-perl | No fix yet | — |
| Ubuntu 22.04 LTS | libcgi-pm-perl | No fix yet | — |
| Ubuntu 20.04 LTS | libcgi-pm-perl | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | libcgi-pm-perl | No fix yet | — |
| Ubuntu 16.04 LTS | libcgi-pm-perl | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | perl-CGI | 5.20.0-1.1 | openSUSE-SU-2026:12465-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | perl-CGI +1 | 5.02-1.amzn2023.0.1 | ALAS2023-2026-3436 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | perl-CGI | No fix yet | — |
Advisories 2
- ALAS2023-2026-3436 Important: perl-CGI security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Nov 12, 2026
- openSUSE-SU-2026:12465-1 perl-CGI-5.20.0-1.1 on GA media SUSE / openSUSE Security Updates · Nov 7, 2026