Vulnerability · Published Nov 3, 2026 · Assigned by CPANSec
CVE-2026-120645CGI versions before 5.00 for Perl allow denial of service via submitted values used as a regex for optgroup selection in scrolling_list
Unrated
In plain English
A regular-expression denial of service in CGI. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities).
Official description
CGI versions before 5.00 for Perl allow denial of service via submitted values used as a regex for optgroup selection in scrolling_list. When rendering option groups, scrolling_list marks the selected options by interpolating each selected value, by default taken from the request parameters, unescaped into a substitution pattern. A client can make the request die with an invalid pattern, or tie up the process with one that backtracks heavily.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120645 |
| Debian:13 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120645 |
| Debian:14 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120645 |
| Ubuntu:22.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120645 |
| Ubuntu:24.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120645 |
| Ubuntu:26.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120645 |
| Ubuntu:26.10 | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120645 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| CGI | 0 – before 5.00 |
Weakness: CWE-1333, CWE-625