CVE-2026-42579
HIGH7.5EPSS 0.03%Netty has a DNS Codec Input Validation Bypass (Encoder + Decoder)
Published: 5/7/2026Modified: 5/19/2026
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.
Affected packages (2)
- Debian/nettyfrom 0
- Maven/io.netty:netty-codec-dns>= 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 |
References (6)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-42579
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-42579
- PATCHhttps://github.com/netty/netty
- WEBhttps://github.com/netty/netty/security/advisories/GHSA-cm33-6792-r9fm
- WEBhttps://tools.ietf.org/html/rfc1035#section-2.3.4
- WEBhttps://tools.ietf.org/html/rfc1035#section-4.1.4