Netty up to 4.2.0.Final/4.2.13.Final TCP Connection release of resource

CVSS Meta Temp Score
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CTI Interest Score
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7.3$0-$5k0.00

Summaryinfo

A vulnerability classified as critical has been found in Netty up to 4.2.0.Final/4.2.13.Final. This impacts an unknown function of the component TCP Connection Handler. This manipulation causes release of resource. This vulnerability is handled as CVE-2026-42577. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Netty up to 4.2.0.Final/4.2.13.Final. Affected by this vulnerability is some unknown processing of the component TCP Connection Handler. The manipulation with an unknown input leads to a release of resource vulnerability. The CWE definition for the vulnerability is CWE-772. The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed. As an impact it is known to affect availability. The summary by CVE is:

Netty is an asynchronous, event-driven network application framework. From 4.2.0.Final to 4.2.13.Final , Netty's epoll transport fails to detect and close TCP connections that receive a RST after being half-closed, leading to stale channels that are never cleaned up and, in some code paths, a 100% CPU busy-loop in the event loop thread. This vulnerability is fixed in 4.2.13.Final.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-42577 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. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 314873 (Linux Distros Unpatched Vulnerability : CVE-2026-42577), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.2.13.Final eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (314873). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.3

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

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

Exploitinginfo

Class: Release of resource
CWE: CWE-772 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 314873
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-42577

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Netty 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
05/15/2026 +2 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-42577 (🔒)
GCVE (CVE): GCVE-0-2026-42577
GCVE (VulDB): GCVE-100-363691

Entryinfo

Created: 05/13/2026 20:52
Updated: 05/15/2026 12:10
Changes: 05/13/2026 20:52 (62), 05/15/2026 12:10 (2)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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