Skip to main content
No exploitation reportedFix available

CVE-2026-120635

CGI versions before 5.00 for Perl allow form fields to be smuggled past proxies and WAFs via multipart parsing that differs from the RFCs

No exploitation reported by the sources we read.

  • Published2026-11-04
  • WeaknessCWE-436

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

CGI versions before 5.00 for Perl allow form fields to be smuggled past proxies and WAFs via multipart parsing that differs from the RFCs. The multipart/form-data parser matches the boundary anywhere rather than at the start of a line, uses the boundary without its leading -- for some client-supplied User-Agent values, finds the Content-Disposition name and filename inside the quoted values of other parameters, and corrupts parts when the boundary nears the 4096-byte read size.

Timeline

dates in UTC
  1. 2026-11-0323:40CVE publishedCNA

Versions per branch

Products declared by the CNA1 product

As CPANSec, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-11-03

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • libcgi-pm-perlUbuntu:26.10all versions · no fixed version listed
  • libcgi-pm-perlUbuntu:26.04:LTSall versions · no fixed version listed
  • libcgi-pm-perlUbuntu:24.04:LTSall versions · no fixed version listed
  • libcgi-pm-perlUbuntu:22.04:LTSall versions · no fixed version listed
  • libcgi-pm-perlUbuntu:20.04:LTSall versions · no fixed version listed
  • libcgi-pm-perlUbuntu:18.04:LTSall versions · no fixed version listed
  • libcgi-pm-perlUbuntu:16.04:LTSall versions · no fixed version listed
  • libcgi-pm-perlDebian:14all versions · no fixed version listed

4 more package ranges on OSV.dev

Vendor advisories

  • CVE-2026-120635 Red Hat Product Security4 known affected

    perl-CGI: perl-CGI: Security control bypass via improper multipart parsing

    perl-CGI.src as a component of Red Hat Enterprise Linux 10 · perl-CGI.src as a component of Red Hat Enterprise Linux 7 · perl-CGI.src as a component of Red Hat Enterprise Linux 8 · +1 more

Full record on NVD

Fix

  1. No fix available, says the vendor Red Hat Product Security CVE-2026-120635 · 4 productsFix deferred

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Published
2026-11-04
Last Modified
2026-11-09
NVD status
Deferred
GitHub Advisory
GHSA-hc7g-hfjx-mc5f

Frequently asked questions

What is CVE-2026-120635?

CGI versions before 5.00 for Perl allow form fields to be smuggled past proxies and WAFs via multipart parsing that differs from the RFCs. The multipart/form-data parser matches the boundary anywhere rather than at the start of a line, uses the boundary without its leading -- for some client-supplied User-Agent values, finds the Content-Disposition name and filename inside the quoted values of other parameters, and corrupts parts when the boundary nears the 4096-byte read size.

Is CVE-2026-120635 actively exploited?

Active exploitation of CVE-2026-120635 has not been confirmed. Its EPSS score was 0.2% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-120635?

CVE-2026-120635 has a CVSS v3 base score of 8.1 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.

Running perl-CGI? Hear about its next vulnerability

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this productCISA KEV additions, November 2026Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database

Sources for this record