Vulnerability · Published Nov 3, 2026 · Assigned by CPANSec
CVE-2026-120632CGI versions before 5.00 for Perl allow CPU exhaustion via a backtracking regex on the XForms multipart/related Content-Type
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 0.2% (higher than 9% of all known vulnerabilities).
Severity (CVSS )–Not rated
Exploit odds (30 days)0.2%top 91.2% 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 CPU exhaustion via a backtracking regex on the XForms multipart/related Content-Type. When a POST Content-Type contains multipart/related, the boundary and start parameters are extracted with an unanchored pattern that puts .+ on either side of the boundary capture, which backtracks in cubic time on a header that does not match. No request body is needed.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120632 |
| Debian:13 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120632 |
| Debian:14 | libcgi-pm-perl | no fix listed | DEBIAN-CVE-2026-120632 |
| Ubuntu:22.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120632 |
| Ubuntu:24.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120632 |
| Ubuntu:26.04:LTS | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120632 |
| Ubuntu:26.10 | libcgi-pm-perl | no fix listed | UBUNTU-CVE-2026-120632 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| CGI | 0 – before 5.00 |
Weakness: CWE-1333