CVE-2026-120632 Details
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.
A denial-of-service vulnerability has been identified in the Perl CGI library, specifically in versions prior to 5.00. The issue arises when a POST request with a multipart/related Content-Type is processed. The library's regex handling of the boundary and start parameters is flawed, allowing for cubic time backtracking on headers that do not match. This exploitation can cause significant CPU exhaustion, with an 8KB header taking approximately 15 seconds to process. Notably, no request body is required to trigger this vulnerability.
Users are advised to upgrade to CGI version 5.00 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Nov 4, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/leejo/CGI.pm/commit/1e529c7ac8d410a51b4b04ab9d6cc00d51ef33c0.patch | CPANSec | Source CodeVendor |
| https://metacpan.org/release/LEEJO/CGI-4.72/source/lib/CGI.pm | CPANSec | Source CodeVendor |
| https://metacpan.org/release/LEEJO/CGI-5.00/changes | CPANSec | AdvisoryBundleVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-1333 | Inefficient Regular Expression Complexity | CPANSec |
Affected Products
| Product | Versions |
|---|---|
| CGI | < 5.00 |
CPE
Remediation
| |
Change History
1 change record found show changes
| Date | Action | Recorded By |
|---|---|---|
| Nov 4, 2026 | New CVE Received | CPANSec |