Network Application Framework Vulnerability in Netty by Netty Project
CVE-2026-42577

7.5HIGH

Key Information:

Vendor

Netty

Status
Netty
Vendor
CVE Published:
13 May 2026

What is CVE-2026-42577?

The Netty framework, an event-driven network application toolkit, contains a vulnerability in its epoll transport mechanism. This flaw affects versions from 4.2.0.Final to 4.2.13.Final by failing to properly manage TCP connections that receive a reset (RST) after a half-closure. As a result, stale channels may accumulate, leading to inefficient resource usage, including a potential 100% CPU busy-loop in the event loop thread. This issue can severely impact application performance and responsiveness, making it crucial for users to upgrade to version 4.2.13.Final or higher, where this vulnerability has been addressed.

Affected Version(s)

netty >= 4.2.0.Final, < 4.2.13.Final

References

https://github.com/netty/netty/security/advisories/GHSA-r...
x_refsource_CONFIRM
https://github.com/netty/netty/pull/16689
x_refsource_MISC
https://github.com/netty/netty/commit/0ec3d97fab376e243d3...
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.