Description
CGI::Carp versions before 5.00 for Perl leak warnings across requests in persistent environments via the warningsToBrowser buffer.
Warnings are held in a package-level buffer until warningsToBrowser writes them into the page as HTML comments, and the buffer is never cleared between requests. Under mod_perl, FastCGI or PSGI, warnings from one request are written into a later one.
Warnings that contain one user's request data can appear in the HTML sent to another user.
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