CVE-2026-59899
Description
Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, `HttpContentEncoder` (the superclass of the production handler `HttpContentCompressor`) maintains a per-channel `ArrayDeque<CharSequence>` named `acceptEncodingQueue` that accumulates attacker-controlled data without any size limit. The queue is filled on the I/O thread for every inbound HTTP request and drained only when the application later writes a non-1xx response. This creates a resource exhaustion vulnerability when an attacker exploits HTTP/1.1 pipelining to flood the connection with requests faster than the application produces responses. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.
How to fix
- netty netty4.1.136, 4.2.16 or later
- io.netty:netty-codec-http4.2.16.Final, 4.1.136.Final or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| netty netty | v < 4.1.136, 4.2.0 ≤ v < 4.2.16 | 4.1.136, 4.2.16 |
| io.netty:netty-codec-httpMaven | 4.2.0.Final ≤ v < 4.2.16.Final, v < 4.1.136.Final | 4.2.16.Final, 4.1.136.Final |
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Attack Surface Management
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