High 7.5Published May 13, 2026

CVE-2026-42577Netty: epoll transport denial of service via RST on half-closed TCP connection

Updated under an hour ago (Oct 27, 2026, 12:10 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-772
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: May 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

netty netty netty:netty (from the name)	from 4.2.0.Final, < 4.2.13.Final	CNA record
netty netty netty:netty	from 4.2.0 before 4.2.13	NVD

References

References

https://github.com/netty/netty/security/advisories/GHSA-rwm7-x88c-3g2p	x-refsource-confirm, mitigation, vendor-advisory
https://github.com/netty/netty/pull/16689	x-refsource-misc, issue-tracking, patch
https://github.com/netty/netty/commit/0ec3d97fab376e243d328ac95fbd288ba0f6e22d	x-refsource-misc, patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.