CPANSA-Plack-App-Prerender-2026-17552: Plack-App-Prerender vulnerability

Publisher giterlizzi Document category csaf_security_advisory
Initial release date 2026-07-27T00:00:00 Engine CSAF Perl Toolkit 0.26
Current release date 2026-07-27T00:00:00 Build Date
Current version 1 Status final
CVSS v3.1 Base Score 9.1 Severity Critical
Original language Language en
Also referred to

Vulnerability Description

Plack::App::Prerender versions before 0.3.0 for Perl can proxy to an arbitrary host via unvalidated REQUEST_URI concatenation in call.

When the rewrite base is a plain string, the REQUEST_URI is appended to it, with no check that the path starts with a forward slash ('/').

When the rewrite base does not contain a path (which is the standard given in the SYNOPSIS), an attacker can create a request that changes the hostname. A request target starting with an at-sign ('@') changes the base to a RFC 3986 userinfo component.

For example, a rewrite base of "https://example.com" with the submitted request "GET @192.168.1.2/" will send a request to "https://example.com@192.168.1.2/", with the rendered content returned to the attacker.

This allows an attacker to access internal or restricted hosts that only the webserver has access to.

Vulnerabilities

CVE-2026-17552

Vulnerability Description

Plack::App::Prerender versions before 0.3.0 for Perl can proxy to an arbitrary host via unvalidated REQUEST_URI concatenation in call.

When the rewrite base is a plain string, the REQUEST_URI is appended to it, with no check that the path starts with a forward slash ('/').

When the rewrite base does not contain a path (which is the standard given in the SYNOPSIS), an attacker can create a request that changes the hostname. A request target starting with an at-sign ('@') changes the base to a RFC 3986 userinfo component.

For example, a rewrite base of "https://example.com" with the submitted request "GET @192.168.1.2/" will send a request to "https://example.com@192.168.1.2/", with the rendered content returned to the attacker.

This allows an attacker to access internal or restricted hosts that only the webserver has access to.

Weakness CWE-918 : Server-Side Request Forgery (SSRF)

Product status

Known affected
Product Score
Plack-App-Prerender less than 0.3.0
CVSS Version CVSS Vector CVSS Base Score CVSS Base Severity
3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N 9.1 Critical
Fixed

giterlizzi

Namespace: https://github.com/giterlizzi/

gdt@cpan.org

References

Revision history

Version Date of the revision Summary of the revision
1 Mon Jul 27 00:00:00 2026 First release

Sharing rules

TLP:WHITE
For the TLP version see: https://www.first.org/tlp/