Vulnerability · Published Nov 3, 2026 · Assigned by CPANSec
CVE-2026-120631CGI::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 parse
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::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 parse. CGI's cookie method reads the Cookie request header through parse, which interpolates the header's expires value unescaped into the substitution pattern that removes it from the cookie string. A client can make the request die with an invalid pattern, or tie up the process with one that backtracks catastrophically.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120631 |
| Debian:13 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120631 |
| Debian:14 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120631 |
| Ubuntu:22.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120631 |
| Ubuntu:24.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120631 |
| Ubuntu:26.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120631 |
| Ubuntu:26.10 | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120631 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| CGI | 4.67 – before 5.00 |
Weakness: CWE-1333, CWE-625