CVE-2026-42579
Netty has a DNS Codec Input Validation Bypass (Encoder + Decoder)
7.5
HIGH
CVSS 3.1
EPSS 0.03%
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.
How to fix CVE-2026-42579
To remediate CVE-2026-42579, upgrade the affected package to a fixed version below.
- —no fix listed
- —upgrade to 4.2.13.Final or later
Is CVE-2026-42579 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0
- >= 4.2.0.Alpha1, < 4.2.13.Final
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |