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

May 6, 2026

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.

References

github.com/advisories/GHSA-rwm7-x88c-3g2p
github.com/netty/netty
github.com/netty/netty/commit/0ec3d97fab376e243d328ac95fbd288ba0f6e22d
github.com/netty/netty/pull/16689
github.com/netty/netty/security/advisories/GHSA-rwm7-x88c-3g2p
nvd.nist.gov/vuln/detail/CVE-2026-42577

Code Behaviors & Features

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