CVE-2026-120638
CGI versions before 5.00 for Perl allow open redirects via HTML entity decoding of the URL after application validation in redirect
Description
CGI versions before 5.00 for Perl allow open redirects via HTML entity decoding of the URL after application validation in redirect. redirect decodes HTML entities in its URL before writing the Location header, so a URL the application has already validated can change meaning. For example, //evil.example/ becomes //evil.example/ and sends the user to another host.
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-2026-120638
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.
- Implement strict URL validation.
- Avoid HTML entity decoding in redirect URLs.
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-2026-120638.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-120638 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-2026-120638
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-2026-120638 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-120638 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 allow open redirects via HTML entity decoding of the URL after application validation in redirect. redirect decodes HTML entities in its URL before writing the Location header, so a URL the application has already validated can change meaning. For example, //evil.example/ becomes //evil.example/ and sends the user to another host. Added CWE CWE-601 Added CWE CWE-180 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/120xxx/CVE-2026-120638.json">CVE-2026-120638</a> Added Reference https://github.com/leejo/CGI.pm/commit/7733c2753f4f240012097507cda2b6e87ae46db4.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