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Plack-1.0055
⭐ Starred 488 / Plack::Loader::Shotgun
Security Advisories (1)
CVE-2026-115825 (2026-10-25)

HTTP::Server::PSGI versions before 1.0056 for Perl allow a single request to crash the server by declaring a large Content-Length. The request body is read with sysread() calls sized by the remaining Content-Length. Perl grows the read buffer to the requested length before any data arrives, so the server tries to allocate as much memory as the client declares. A remote attacker can send one request with a large Content-Length and a few body bytes, and perl exits with an out-of-memory error before the application is called. HTTP::Server::PSGI runs as a single process, so the server stays down until restarted.

NAME

Plack::Loader::Shotgun - forking implementation of plackup

SYNOPSIS

plackup -L Shotgun

DESCRIPTION

Shotgun loader delays the compilation and execution of your application until the runtime. When a new request comes in, this forks a new child, compiles your code and runs the application.

This should be an ultimate alternative solution when reloading with Plack::Middleware::Refresh doesn't work, or plackup's default -r filesystem watcher causes problems. I can imagine this is useful for applications which expects their application is only evaluated once (like in-file templates) or on operating systems with broken fork implementation, etc.

This is much like good old CGI's fork and run but you don't need a web server, and there's a benefit of preloading modules that are not likely to change. For instance if you develop a web application using Moose and DBIx::Class,

plackup -MMoose -MDBIx::Class -L Shotgun yourapp.psgi

would preload those modules and only re-evaluates your code in every request.

AUTHOR

Tatsuhiko Miyagawa with an inspiration from http://github.com/rtomayko/shotgun

SEE ALSO

plackup