Vulnerability · Published May 13, 2026 · Assigned by GitHub_M
CVE-2026-42586Netty: CRLF Injection in Netty Redis Codec Encoder
Medium 6.8
In plain English
A medium-severity security flaw in netty-codec-redis from io.netty. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | netty | no fix listed | DEBIAN-CVE-2026-42586 |
| Debian:13 | netty | no fix listed | DEBIAN-CVE-2026-42586 |
| Debian:14 | netty | no fix listed | DEBIAN-CVE-2026-42586 |
| Maven | io.netty:netty-codec-redis | 4.1.133.Final | GHSA-rgrr-p7gp-5xj7 |
| Maven | io.netty:netty-codec-redis | 4.2.13.Final | GHSA-rgrr-p7gp-5xj7 |
| Ubuntu:25.10 | netty | no fix listed | UBUNTU-CVE-2026-42586 |
| Ubuntu:26.10 | netty | no fix listed | UBUNTU-CVE-2026-42586 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| netty | netty | >= 4.2.0.Alpha1, < 4.2.13.Final< 4.1.133.Final |
| io.netty | netty-codec-redis | >= 4.2.0.Alpha1, < 4.2.13.Final< 4.1.133.Final |
Weakness: CWE-93 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
References
- https://github.com/netty/netty/security/advisories/GHSA-rgrr-p7gp-5xj7 x_refsource_CONFIRM