CVE-2026-42577

⚠️ high

Summary

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.

CVSS Score

7.5

High

EPSS Score

0.1

Exploit Probability

Published Date

2026-05-13

First Seen: 2026-05-17

📊 Relative Risk Intelligence

This CVE is Moderate Risk - more severe than 67.7% of all 365,312 vulnerabilities in our database.

#117,872

Above average severity

Severity Percentile

🎯 CISA SSVC Assessment Updated: May 14, 2026

🔍 Exploitation Status

None

No known exploits

⚙️ Automatable

YES

Can be exploited automatically

💥 Technical Impact

Partial

Limited system impact

SSVC data provided by CISA

Last Modified 2026-05-18

Source NVD 🔗

CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE IDs (Weakness Types)

CWE-772

📦 Affected Products 1

Vendor	Product	Status	Affected Versions
netty	netty	Affected	> 4.2.0 < 4.2.13

🔗 References 3

https://github.com/netty/netty/commit/0ec3d97fab376e...

Patch

https://github.com/netty/netty/pull/16689

Issue Tracking Patch

https://github.com/netty/netty/security/advisories/G...

Mitigation Vendor Advisory

🔗 Related CVEs 6

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-89044	🔶 medium	6.5	0.4	Netty versions 4.1.133.Final through 4.1.137.Final and 4.2.13.Final through 4.2.17.Final fail to properly validate the f...	2026-09-10
CVE-2026-62380	⚠️ high	7.5	0.3	Netty (io.netty:netty-codec-socks) versions 4.2.0.Final through 4.2.16.Final and 4.1.x through 4.1.136.Final contain nul...	2026-08-22
CVE-2026-75595	⛔ critical	9.1	0.5	Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Fina and 4.2.17.Final, io.netty.h...	2026-08-19
CVE-2026-75596	⚠️ high	7.5	0.7	Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the defau...	2026-08-19
CVE-2026-59902	⚠️ high	7.5	0.7	Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, io.netty....	2026-08-17
CVE-2026-59903	🔶 medium	6.5	0.3	Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, io.netty....	2026-08-17

These CVEs affect the same products