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Plack-1.0055
⭐ Starred 488 / Plack::Loader
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 - (auto)load Plack Servers

SYNOPSIS

# auto-select server backends based on env vars
use Plack::Loader;
Plack::Loader->auto(%args)->run($app);

# specify the implementation with a name
Plack::Loader->load('FCGI', %args)->run($app);

DESCRIPTION

Plack::Loader is a factory class to load one of Plack::Handler subclasses based on the environment.

AUTOLOADING

Plack::Loader->auto(%args) will autoload the most correct server implementation by guessing from environment variables and Perl INC hashes.

PLACK_SERVER
env PLACK_SERVER=AnyEvent ...

Plack users can specify the specific implementation they want to load using the PLACK_SERVER environment variable.

PHP_FCGI_CHILDREN, GATEWAY_INTERFACE

If there's one of FastCGI or CGI specific environment variables set, use the corresponding server implementation.

%INC

If one of AnyEvent, Coro or POE is loaded, the relevant server implementation such as Twiggy, Corona or POE::Component::Server::PSGI will be loaded, if they're available.