Allocation of Resources Without Limits or Throttling The advisory has been revoked - it doesn't affect any version of package io.netty:netty-codec-http (opens in a new tab)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-JAVA-IONETTY-20154837
- published27 Sept 2026
- disclosed26 Sept 2026
- creditRajivarnan R
Introduced: 26 Sep 2026
NewCVE-2026-100658 (opens in a new tab)How to fix?
Upgrade io.netty:netty-codec-http to version 4.1.138.Final, 4.2.18.Final or higher.
Amendment
This was deemed not a vulnerability.
Overview
io.netty:netty-codec-http is a network application framework for rapid development of maintainable high performance protocol servers & clients.
Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling in WebSocketServerExtensionHandler, whose per-connection validExtensions queue takes an entry for every inbound request in onHttpRequestChannelRead() with no size check, and drains only when the application writes a response through onHttpResponseWrite(). An attacker can drive the server to OutOfMemoryError by holding a connection open and pipelining well-formed HTTP/1.1 requests faster than responses are written, since every queued entry is retained until the connection closes. This requires WebSocket compression to be enabled through WebSocketServerCompressionHandler and an application that performs asynchronous work before responding, and at roughly 100 bytes of heap per request the cost approximates the wire cost, making this accumulation rather than amplification, with no WebSocket upgrade needed to reach it.
Note: CVE-2026-100658 was rejected by the CVE List.