CVE-2026-50020

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, before reading the first request-line, HttpObjectDecoder skips every byte for which Character.isISOControl(b) is true (0x00–0x1F and 0x7F) as well as all whitespace. RFC 9112 §2.2 only asks servers to ignore empty CRLF lines preceding the request-line — a carefully scoped robustness allowance intended to handle HTTP/1.0 POST workarounds. Silently absorbing NUL bytes, SOH, STX, and other non-CRLF control characters goes significantly beyond this, and can be exploited for request-boundary confusion in pipelined or multiplexed transports where a front-end component treats those bytes differently. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Database specific

{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50020.json",
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-444"
    ]
}

References

Affected packages

Git / github.com/netty/netty

Affected ranges

Type

GIT

Repo

https://github.com/netty/netty

Events

Introduced

Fixed

f05f765d81460799c53123a207f665bf3b465171

Introduced

09e64d259c99be8b5b2a471a78f11e65eb82598a

Fixed

a41f7b289ce1d697c50846f3ade3983e22b2ed40

Database specific

{
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ],
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "4.1.135"
        },
        {
            "introduced": "4.2.0"
        },
        {
            "fixed": "4.2.15"
        }
    ],
    "cpe": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*"
}

Affected versions

netty-4.*

netty-4.0.0.Alpha1

netty-4.0.0.Alpha2

netty-4.0.0.Alpha3

netty-4.0.0.Alpha4

netty-4.0.0.Alpha5

netty-4.0.0.Alpha6

netty-4.0.0.Alpha7

netty-4.0.0.Alpha8

netty-4.0.0.Beta1

netty-4.0.0.Beta2

netty-4.0.0.Beta3

netty-4.0.0.CR1

netty-4.0.0.CR2

netty-4.0.0.CR3

netty-4.0.0.CR4

netty-4.0.0.CR5

netty-4.0.0.CR7

netty-4.0.0.CR8

netty-4.0.0.CR9

netty-4.0.0.Final

netty-4.0.1.Final

netty-4.0.10.Final

netty-4.0.11.Final

netty-4.0.12.Final

netty-4.0.13.Final

netty-4.0.14.Beta1

netty-4.0.14.Final

netty-4.0.15.Final

netty-4.0.2.Final

netty-4.0.3.Final

netty-4.0.4.Final

netty-4.0.5.Final

netty-4.0.6.Final

netty-4.0.7.Final

netty-4.0.8.Final

netty-4.1.0.Beta1

netty-4.1.0.Beta2

netty-4.1.0.Beta3

netty-4.1.0.Beta4

netty-4.1.0.Beta5

netty-4.1.0.Beta6

netty-4.1.0.Beta7

netty-4.1.0.Beta8

netty-4.1.0.CR1

netty-4.1.0.CR2

netty-4.1.0.CR3

netty-4.1.0.CR4

netty-4.1.0.CR5

netty-4.1.0.CR6

netty-4.1.0.CR7

netty-4.1.0.Final

netty-4.1.1.Final

netty-4.1.10.Final

netty-4.1.100.Final

netty-4.1.101.Final

netty-4.1.102.Final

netty-4.1.103.Final

netty-4.1.104.Final

netty-4.1.105.Final

netty-4.1.106.Final

netty-4.1.107.Final

netty-4.1.108.Final

netty-4.1.109.Final

netty-4.1.11.Final

netty-4.1.110.Final

netty-4.1.111.Final

netty-4.1.112.Final

netty-4.1.113.Final

netty-4.1.114.Final

netty-4.1.115.Final

netty-4.1.116.Final

netty-4.1.117.Final

netty-4.1.118.Final

netty-4.1.119.Final

netty-4.1.12.Final

netty-4.1.120.Final

netty-4.1.121.Final

netty-4.1.122.Final

netty-4.1.123.Final

netty-4.1.124.Final

netty-4.1.125.Final

netty-4.1.126.Final

netty-4.1.127.Final

netty-4.1.128.Final

netty-4.1.129.Final

netty-4.1.13.Final

netty-4.1.130.Final

netty-4.1.131.Final

netty-4.1.132.Final

netty-4.1.133.Final

netty-4.1.134.Final

netty-4.1.14.Final

netty-4.1.15.Final

netty-4.1.16.Final

netty-4.1.17.Final

netty-4.1.18.Final

netty-4.1.19.Final

netty-4.1.2.Final

netty-4.1.20.Final

netty-4.1.21.Final

netty-4.1.22.Final

netty-4.1.23.Final

netty-4.1.24.Final

netty-4.1.25.Final

netty-4.1.26.Final

netty-4.1.27.Final

netty-4.1.28.Final

netty-4.1.29.Final

netty-4.1.3.Final

netty-4.1.30.Final

netty-4.1.31.Final

netty-4.1.32.Final

netty-4.1.33.Final

netty-4.1.34.Final

netty-4.1.35.Final

netty-4.1.36.Final

netty-4.1.37.Final

netty-4.1.38.Final

netty-4.1.39.Final

netty-4.1.4.Final

netty-4.1.40.Final

netty-4.1.41.Final

netty-4.1.42.Final

netty-4.1.43.Final

netty-4.1.44.Final

netty-4.1.45.Final

netty-4.1.46.Final

netty-4.1.47.Final

netty-4.1.48.Final

netty-4.1.49.Final

netty-4.1.5.Final

netty-4.1.50.Final

netty-4.1.51.Final

netty-4.1.52.Final

netty-4.1.53.Final

netty-4.1.54.Final

netty-4.1.55.Final

netty-4.1.56.Final

netty-4.1.57.Final

netty-4.1.58.Final

netty-4.1.59.Final

netty-4.1.6.Final

netty-4.1.60.Final

netty-4.1.61.Final

netty-4.1.62.Final

netty-4.1.63.Final

netty-4.1.64.Final

netty-4.1.65.Final

netty-4.1.66.Final

netty-4.1.67.Final

netty-4.1.68.Final

netty-4.1.69.Final

netty-4.1.7.Final

netty-4.1.70.Final

netty-4.1.71.Final

netty-4.1.72.Final

netty-4.1.73.Final

netty-4.1.74.Final

netty-4.1.75.Final

netty-4.1.76.Final

netty-4.1.77.Final

netty-4.1.78.Final

netty-4.1.79.Final

netty-4.1.8.Final

netty-4.1.80.Final

netty-4.1.81.Final

netty-4.1.82.Final

netty-4.1.83.Final

netty-4.1.84.Final

netty-4.1.85.Final

netty-4.1.86.Final

netty-4.1.87.Final

netty-4.1.88.Final

netty-4.1.89.Final

netty-4.1.9.Final

netty-4.1.90.Final

netty-4.1.91.Final

netty-4.1.92.Final

netty-4.1.93.Final

netty-4.1.94.Final

netty-4.1.95.Final

netty-4.1.96.Final

netty-4.1.97.Final

netty-4.1.98.Final

netty-4.1.99.Final

netty-4.2.0.Final

netty-4.2.1.Final

netty-4.2.10.Final

netty-4.2.11.Final

netty-4.2.12.Final

netty-4.2.13.Final

netty-4.2.14.Final

netty-4.2.2.Final

netty-4.2.3.Final

netty-4.2.4.Final

netty-4.2.5.Final

netty-4.2.6.Final

netty-4.2.7.Final

netty-4.2.8.Final

netty-4.2.9.Final

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-50020.json"