# CVE-2025-4366: Request Smuggling Vulnerability in Pingora

> Attackers can smuggle requests and poison caches in Pingora proxying frameworks when caching is enabled, requiring a patch to mitigate.

- **Severity:** High 7.4 (`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 22 May 2025
- **Updated:** 18 Jun 2025
- **Also known as:** GHSA-93c7-7xqw-w357, RUSTSEC-2025-0037

## What is CVE-2025-4366?

CVE-2025-4366 is a high-severity vulnerability in cloudflare:pingora, published on 22 May 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

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.

Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests)

## Which versions are affected by CVE-2025-4366?

3 open source packages ship an affected version, including pingora-core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `pingora-core` | crates.io | All versions | 0.5.0 |
| `pingora-core` | crates.io | All versions | 0.5.0 |
| `pingora-core` | crates.io | From 0.0.0-0 | 0.5.0 |

Products: Cloudflare Pingora.

## How do I fix CVE-2025-4366?

Upgrade pingora-core to 0.5.0 or later.

## Is CVE-2025-4366 being exploited?

There is no known exploitation of CVE-2025-4366 in the wild and no public exploit code.

## Other vulnerabilities in cloudflare:pingora

- [CVE-2026-2833](https://insights.sbomify.com/CVE-2026-2833/): HTTP Request Smuggling via Premature Upgrade (critical 9.3)
- [CVE-2026-2835](https://insights.sbomify.com/CVE-2026-2835/): HTTP Request Smuggling via HTTP/1.0 and Transfer-Encoding Misparsing (critical 9.3)
- [CVE-2026-2836](https://insights.sbomify.com/CVE-2026-2836/): Cache poisoning via insecure-by-default cache key (high 8.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-4366 and fix it if it is affected.

What it is: CVE-2025-4366 is a high-severity vulnerability in cloudflare:pingora, published on 22 May 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-4366 in the wild and no public exploit code.

Affected packages and fixed versions:
- pingora-core (crates.io): affected all versions; fixed in 0.5.0
- pingora-core (crates.io): affected all versions; fixed in 0.5.0
- pingora-core (crates.io): affected from 0.0.0-0; fixed in 0.5.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-4366/ (Markdown: https://insights.sbomify.com/CVE-2025-4366/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-4366
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-4366
- OSV: https://osv.dev/vulnerability/CVE-2025-4366

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-4366/
Summaries are generated and may contain mistakes; the official description above is the record.