CVE-2026-42579

HIGH 7.5

Netty: DNS Codec Input Validation Bypass in Netty (Encoder + Decoder)

CVSS Score

7.5

EPSS Score

1.0%

EPSS Percentile

58th

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the decoder, and user-influenced hostnames can exploit the encoder. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

CWE	CWE-20 CWE-400 CWE-626
Vendor	netty
Product	netty
Published	May 13, 2026
Last Updated	Aug 6, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Affected Versions

netty / netty

>= 4.2.0.Alpha1, < 4.2.13.Final < 4.1.133.Final

References

NVD ↗ CVE.org ↗ EPSS Data ↗