/ 
Plack-1.0053
⭐ Starred 488 / Plack::Middleware::ErrorDocument
Security Advisories (1)
CVE-2026-7381 (2026-04-29)

Plack::Middleware::XSendfile versions through 1.0053 for Perl can allow client-controlled path rewriting. Plack::Middleware::XSendfile allows the variation setting (sendfile type) to be set by the client via the X-Sendfile-Type header, if it is not considered in the middleware constructor or the Plack environment. A malicious client can set the X-Sendfile-Type header to "X-Accel-Redirect" to services running behind nginx reverse proxies, and then set the X-Accel-Mapping to map the path to an arbitrary file on the server. Since 1.0053, Plack::Middleware::XSendfile is deprecated and will be removed from future releases of Plack. This is similar to CVE-2025-61780 for Rack::Sendfile, although Plack::Middleware::XSendfile has some mitigations that disallow regular expressions to be used in the mapping, and only apply the mapping for the "X-Accel-Redirect" type.

NAME

Plack::Middleware::ErrorDocument - Set Error Document based on HTTP status code

SYNOPSIS

# in app.psgi
use Plack::Builder;

builder {
    enable "Plack::Middleware::ErrorDocument",
        500 => '/uri/errors/500.html', 404 => '/uri/errors/404.html',
        subrequest => 1;
    $app;
};

DESCRIPTION

Plack::Middleware::ErrorDocument allows you to customize error screen by setting paths (file system path or URI path) of error pages per status code.

CONFIGURATIONS

subrequest

A boolean flag to serve error pages using a new GET sub request. Defaults to false, which means it serves error pages using file system path.

builder {
    enable "Plack::Middleware::ErrorDocument",
        502 => '/home/www/htdocs/errors/maint.html';
    enable "Plack::Middleware::ErrorDocument",
        404 => '/static/404.html', 403 => '/static/403.html', subrequest => 1;
    $app;
};

This configuration serves 502 error pages from file system directly assuming that's when you probably maintain database etc. but serves 404 and 403 pages using a sub request so your application can do some logic there like logging or doing suggestions.

When using a subrequest, the subrequest should return a regular '200' response.

AUTHOR

Tatsuhiko Miyagawa

SEE ALSO