/ 
Plack-1.0055
⭐ Starred 488 / Plack::Middleware::ConditionalGET
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::Middleware::ConditionalGET - Middleware to enable conditional GET

SYNOPSIS

builder {
    enable "ConditionalGET";
    ....
};

DESCRIPTION

This middleware enables conditional GET and HEAD using If-None-Match and If-Modified-Since header. The application should set either or both of Last-Modified or ETag response headers per RFC 2616. When either of the conditions is met, the response body is set to be zero length and the status is set to 304 Not Modified.

SEE ALSO

Rack::ConditionalGet