netty netty-codec-http up to 4.1.133.Final/4.2.13.Final queue.poll request smuggling

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.8$0-$5k0.00

Summaryinfo

A vulnerability marked as critical has been reported in netty netty-codec-http up to 4.1.133.Final/4.2.13.Final. Affected is the function queue.poll. This manipulation causes request smuggling. This vulnerability appears as CVE-2026-42584. The attack may be initiated remotely. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in netty netty-codec-http up to 4.1.133.Final/4.2.13.Final and classified as critical. Affected by this vulnerability is the function queue.poll. The manipulation with an unknown input leads to a request smuggling vulnerability. The CWE definition for the vulnerability is CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103, then 200 with GET body, then 200 for HEAD, the queue pairs HEAD with the first 200. The HEAD rule then skips reading that message’s body, so the GET entity bytes stay on the stream and the following 200 is parsed from the wrong offset. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-42584 since 04/28/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 321020 (SUSE SLED15 / SLES15 Security Update : netty, netty-tcnative (SUSE-SU-2026:2308-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.1.133.Final or 4.2.13.Final eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (321020). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.8

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 9.1
NVD Vector: 🔒

CNA Base Score: 7.3
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Request smuggling
CWE: CWE-444
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 321020
Nessus Name: SUSE SLED15 / SLES15 Security Update : netty, netty-tcnative (SUSE-SU-2026:2308-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: netty-codec-http 4.1.133.Final/4.2.13.Final

Timelineinfo

04/28/2026 CVE reserved
05/13/2026 +15 days Advisory disclosed
05/13/2026 +0 days VulDB entry created
06/15/2026 +33 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-42584 (🔒)
GCVE (CVE): GCVE-0-2026-42584
GCVE (VulDB): GCVE-100-363703

Entryinfo

Created: 05/13/2026 21:03
Updated: 06/15/2026 04:35
Changes: 05/13/2026 21:03 (63), 05/19/2026 10:31 (11), 06/15/2026 04:35 (2)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you need the next level of professionalism?

Upgrade your account now!