CVE-2026-59899
Netty HttpContentEncoder: Unbounded Per-Connection Queue Growth via HTTP/1.1 Pipelining Leads to Denial of Service
- State
- Published
- Severity
- 6.9 Medium
- Published
- Jul 29, 2026
- Updated
- Jul 30, 2026
- Reserved
- Jul 7, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.9 Medium | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N | GitHub_M |
Weaknesses
- CWE-770 Allocation of Resources Without Limits or Throttling
Affected Products
| Product | Versions |
|---|---|
nettynetty |
|
References
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