CVE-2025-4366: Cloudflare Pingora

Medium severity, CVSS 6.1. EPSS: 0.5% chance of exploitation in the next 30 days.

A request smuggling vulnerability identified within Pingora’s proxying framework, pingora-proxy, allows malicious HTTP requests to be injected via manipulated request bodies on cache HITs, leading to unauthorized request execution and potential cache poisoning. Fixed in:  https://github.com/cloudflare/pingora/commit/fda3317ec822678564d641e7cf1c9b77ee3759ff https://github.com/cloudflare/pingora/commit/fda3317ec822678564d641e7cf1c9b77ee3759ff Impact: The issue could lead to request smuggling in cases where Pingora’s proxying framework, pingora-proxy, is used for caching allowing an attacker to manipulate headers and URLs in subsequent requests made on the same HTTP/1.1 connection.

Affected products

• Cloudflare Pingora: before 0.5.0 (fixed in 0.5.0)

Published 2025-05-22. Last modified 2026-06-17.