CVE-2025-40927
CVE-2025-40927CVE-2025-40927
Description
CGI::Simple versions before 1.282 for Perl has a HTTP response splitting flaw
This vulnerability is a confirmed HTTP response splitting flaw in CGI::Simple that allows HTTP response header injection, which can be used for reflected XSS or open redirect under certain conditions.
Although some validation exists, it can be bypassed using URL-encoded values, allowing an attacker to inject untrusted content into the response via query parameters.
As a result, an attacker can inject a line break (e.g. %0A) into the parameter value, causing the server to split the HTTP response and inject arbitrary headers or even an HTML/JavaScript body, leading to reflected cross-site scripting (XSS), open redirect or other attacks.
The issue documented in CVE-2010-4410 https://www.cve.org/CVERecord?id=CVE-2010-4410 is related but the fix was incomplete.
Impact
By injecting %0A (newline) into a query string parameter, an attacker can:
* Break the current HTTP header
* Inject a new header or en
Scoring
| CVSS | 7.3 () |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| Last modified | 2026-10-18 |