CVE-2026-42577

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

HIGH
7.5
CVSS Score
Published: May 13, 2026 at 06:00 PM UTC
Updated: June 17, 2026 at 10:48 AM UTC
1 product affected across 1 vendorNetty

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Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.2.13.Final4.2.0 ≤ v < 4.2.13
Affected range stops below 4.2.13.Final, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_CONFIRMMitigationVendor Advisory
Source: cverecord
https://github.com/netty/netty/security/advisories/GHSA-rwm7-x88c-3g2p
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/netty/netty/pull/16689

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-772

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