CVSS 4.0
6.9 mediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NCVE-2026-59899
Medium (6.9) in netty netty. EPSS 0.6% chance of exploitation in the next 30 days. Fixed in io.netty:netty-codec-http 4.1.136.Final, 4.2.16.Final.
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.
Severity
CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- EPSS
- 0.6% chance of exploitation in the next 30 days; higher than 49% of CVEs (scores of 2026-10-31)
- CWE
- CWE-770
- Published
- Modified
- Record from
- the NVD, synced
Affected
- netty:netty
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-q4f6-jm68-57ww | Maven | io.netty:netty-codec-http | >=4.2.0.Final <4.2.16.Final | 4.2.16.Final |
| GHSA-q4f6-jm68-57ww | Maven | io.netty:netty-codec-http | <4.1.136.Final | 4.1.136.Final |