CVE-2026-42586— Netty: CRLF Injection in Netty Redis Codec Encoder
Quick assessment
Affected
netty netty
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
Netty是Netty社区的一款非阻塞I/O客户端-服务器框架，它主要用于开发Java网络应用程序，如协议服务器和客户端等。 Netty 4.2.13.Final和4.1.133.Final之前版本存在注入漏洞，该漏洞源于Redis编码器未验证或清理CRLF字符，可能导致注入任意Redis命令或伪造响应。
Possible ATT&CK Techniques 2 AI
T1059 · Command and Scripting Interpreter T1190 · Exploit Public-Facing ApplicationAffected Version Matrix 4
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| io.netty | netty-codec-redis | >= 4.2.0.Alpha1, < 4.2.13.Final |
affected |
< 4.1.133.Final |
affected | ||
| netty | netty | >= 4.2.0.Alpha1, < 4.2.13.Final |
affected |
< 4.1.133.Final |
affected |
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I. Basic Information for CVE-2026-42586
Vulnerability Information
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Vulnerability Title
Netty: CRLF Injection in Netty Redis Codec Encoder
Source: CVE Program / CVE List V5
Vulnerability Description
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, the Netty Redis codec encoder (RedisEncoder) writes user-controlled string content directly to the network output buffer without validating or sanitizing CRLF (\r\n) characters. Since the Redis Serialization Protocol (RESP) uses CRLF as the command/response delimiter, an attacker who can control the content of a Redis message can inject arbitrary Redis commands or forge fake responses. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
对CRLF序列的转义处理不恰当(CRLF注入)
Source: CVE Program / CVE List V5
Vulnerability Title
Netty 注入漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Netty是Netty社区的一款非阻塞I/O客户端-服务器框架，它主要用于开发Java网络应用程序，如协议服务器和客户端等。 Netty 4.2.13.Final和4.1.133.Final之前版本存在注入漏洞，该漏洞源于Redis编码器未验证或清理CRLF字符，可能导致注入任意Redis命令或伪造响应。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| netty | netty | >= 4.2.0.Alpha1, < 4.2.13.Final | - |
|
| io.netty | netty-codec-redis | >= 4.2.0.Alpha1, < 4.2.13.Final | - |
|
II. Public POCs for CVE-2026-42586
| # | POC Description | Source Link | Shenlong Link |
|---|
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Vendor Advisories for CVE-2026-42586 (1)
Same Patch Batch · netty · 2026-05-13 · 12 CVEs total
| CVE-2026-42587 | 7.5 HIGH | Netty: HttpContentDecompressor maxAllocation bypass via Content-Encoding: br/zstd/snappy e |
| CVE-2026-42582 | 7.5 HIGH | Netty: HTTP/3 QPACK literal unbounded allocation |
| CVE-2026-42579 | 7.5 HIGH | Netty: DNS Codec Input Validation Bypass in Netty (Encoder + Decoder) |
| CVE-2026-42583 | 7.5 HIGH | Netty: Lz4FrameDecoder resource exhaustion |
| CVE-2026-42577 | 7.5 HIGH | Netty: epoll transport denial of service via RST on half-closed TCP connection |
| CVE-2026-42584 | 7.3 HIGH | Netty: HttpClientCodec response desynchronization |
| CVE-2026-42580 | 6.5 MEDIUM | Netty: HTTP Request Smuggling due to incorrect chunk size parsing |
| CVE-2026-42585 | 6.5 MEDIUM | Netty: HTTP Request Smuggling due to malformed Transfer-Encoding |
| CVE-2026-42581 | 5.8 MEDIUM | Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization |
| CVE-2026-44248 | 5.3 MEDIUM | Netty: Resource exhaustion in MqttDecoder |
| CVE-2026-42578 | 2.9 LOW | Netty: HTTP Header Injection via HttpProxyHandler Disabled Validation |
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Same vendor: netty
-
CVE-2026-76816
Netty: MQTT Topic Name and Client ID Validation Bypass -
CVE-2026-62380
Netty before 4.2.16.Final SOCKS Proxy Null Byte Injection -
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Same weakness: CWE-93
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V. Comments for CVE-2026-42586
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