8.2
HIGH CVSS 4.0
CVE-2025-58056
Netty HTTP Request Smuggling Vulnerability
Description

Netty is an asynchronous event-driven network application framework for development of maintainable high performance protocol servers and clients. In versions 4.1.124.Final, and 4.2.0.Alpha3 through 4.2.4.Final, Netty incorrectly accepts standalone newline characters (LF) as a chunk-size line terminator, regardless of a preceding carriage return (CR), instead of requiring CRLF per HTTP/1.1 standards. When combined with reverse proxies that parse LF differently (treating it as part of the chunk extension), attackers can craft requests that the proxy sees as one request but Netty processes as two, enabling request smuggling attacks. This is fixed in versions 4.1.125.Final and 4.2.5.Final.

INFO

Published Date :

Sept. 3, 2025, 9:15 p.m.

Last Modified :

Sept. 3, 2025, 9:15 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2025-58056 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 HIGH [email protected]
Solution
Update Netty to a version that correctly handles HTTP/1.1 chunked encoding terminators.
  • Update Netty to version 4.1.125.Final or later.
  • Update Netty to version 4.2.5.Final or later.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-58056 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-58056 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-58056 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-58056 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 03, 2025

    Action Type Old Value New Value
    Added Description Netty is an asynchronous event-driven network application framework for development of maintainable high performance protocol servers and clients. In versions 4.1.124.Final, and 4.2.0.Alpha3 through 4.2.4.Final, Netty incorrectly accepts standalone newline characters (LF) as a chunk-size line terminator, regardless of a preceding carriage return (CR), instead of requiring CRLF per HTTP/1.1 standards. When combined with reverse proxies that parse LF differently (treating it as part of the chunk extension), attackers can craft requests that the proxy sees as one request but Netty processes as two, enabling request smuggling attacks. This is fixed in versions 4.1.125.Final and 4.2.5.Final.
    Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-444
    Added Reference https://datatracker.ietf.org/doc/html/rfc9112#name-chunked-transfer-coding
    Added Reference https://github.com/JLLeitschuh/unCVEed/issues/1
    Added Reference https://github.com/netty/netty/commit/edb55fd8e0a3bcbd85881e423464f585183d1284
    Added Reference https://github.com/netty/netty/issues/15522
    Added Reference https://github.com/netty/netty/pull/15611
    Added Reference https://github.com/netty/netty/security/advisories/GHSA-fghv-69vj-qj49
    Added Reference https://w4ke.info/2025/06/18/funky-chunks.html
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 8.2
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability