CVE-2026-120633
CGI versions before 5.00 for Perl trust the client X-Forwarded-Host header in url, self_url, virtual_host and virtual_port
Description
CGI versions before 5.00 for Perl trust the client X-Forwarded-Host header in url, self_url, virtual_host and virtual_port. These take the host name and port from the X-Forwarded-Host request header when present, and otherwise from Host, without validating either. The URLs from url and self_url are the default redirect location and the start_html(-base=>1) base href, and the default start_form action when REQUEST_URI is not set. A client can poison shared caches, and URLs the application stores or sends, with redirects, links and scripts that point at a host it controls.
INFO
Published Date :
Nov. 4, 2026, 12:17 a.m.
Last Modified :
Nov. 4, 2026, 12:17 a.m.
Remotely Exploit :
No
Source :
9b29abf9-4ab0-4765-b253-1875cd9b441e
Affected Products
The following products are affected by CVE-2026-120633
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update CGI to version 5.00 or later.
- Validate all incoming client-provided headers.
- Disable trust of X-Forwarded-Host header.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-120633.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-120633 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-120633
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-120633 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-120633 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 9b29abf9-4ab0-4765-b253-1875cd9b441e
Nov. 04, 2026
Action Type Old Value New Value Added Description CGI versions before 5.00 for Perl trust the client X-Forwarded-Host header in url, self_url, virtual_host and virtual_port. These take the host name and port from the X-Forwarded-Host request header when present, and otherwise from Host, without validating either. The URLs from url and self_url are the default redirect location and the start_html(-base=>1) base href, and the default start_form action when REQUEST_URI is not set. A client can poison shared caches, and URLs the application stores or sends, with redirects, links and scripts that point at a host it controls. Added CWE CWE-601 Added CWE CWE-348 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/120xxx/CVE-2026-120633.json">CVE-2026-120633</a> Added Reference https://github.com/leejo/CGI.pm/commit/d76752a5e8dfd365b0fe3a0b9a7da6c054e856af.patch Added Reference https://metacpan.org/release/LEEJO/CGI-4.72/source/lib/CGI.pm Added Reference https://metacpan.org/release/LEEJO/CGI-5.00/changes