Vulnerability · Published Jul 27, 2026 · Assigned by CPANSec
CVE-2026-17552Plack::App::Prerender versions before 0.3.0 for Perl can proxy to an arbitrary host via unvalidated REQUEST_URI concatenation in call
Critical 9.1
In plain English
A critical-severity server-side request forgery in Plack::App::Prerender from RRWO. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| RRWO | Plack::App::Prerender | 0 – before 0.3.0 |
Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
References
- https://github.com/robrwo/perl-Plack-App-Prerender/security/advisories/GHSA-6x4w-x68j-ppqq vendor-advisory
- https://metacpan.org/release/RRWO/Plack-App-Prerender-v0.3.0/changes release-notes
- https://github.com/robrwo/perl-Plack-App-Prerender/commit/2d793dd69e2b6f4e469618ee742bd8402677202d.patch patch
- http://www.openwall.com/lists/oss-security/2026/07/28/3