Vulnerability in Cloudflare Pingora
CVE-2025-4366
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.
Vulnerability class: HTTP Request Smuggling
EPSS: 0.004 (34.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cna@cloudflare.com (Product)
Frequently asked questions
- What is CVE-2025-4366?
- CVE-2025-4366 is a medium-severity vulnerability in Cloudflare Pingora, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 6.1/10. Published 2025-05-22.
- How severe is CVE-2025-4366?
- Medium severity. CVSS v3 base score is 6.1 out of 10.
- Is CVE-2025-4366 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.