CVE-2026-42579

HIGH

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

Title source: cna
STIX 2.1

Description

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.

References (1)

Core 1
Core References

Scores

CVSS v3 7.5
EPSS 0.0042
EPSS Percentile 33.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-20 CWE-400 CWE-626
Status published
Products (5)
io.netty/netty-codec-dns 0 - 4.1.133.FinalMaven
io.netty/netty-codec-dns 4.2.0.Alpha1 - 4.2.13.FinalMaven
netty/netty < 4.1.133
netty/netty < 4.1.133.Final
netty/netty >= 4.2.0.Alpha1, < 4.2.13.Final
Published May 13, 2026
Tracked Since May 14, 2026