CVE-2026-42577
Netty epoll transport denial of service via RST on half-closed TCP connection
7.5
HIGH
CVSS 3.1
EPSS 0.05%
Description
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.
How to fix CVE-2026-42577
To remediate CVE-2026-42577, upgrade the affected package to a fixed version below.
- —no fix listed
- —upgrade to 4.2.13.Final or later
Is CVE-2026-42577 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0
- >= 4.2.0.Final, < 4.2.13.Final
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |