CVE-2026-45673

Netty: DNS Cache Poisoning due to Predictable PRNG and Default Static Source Port

State: Published
Severity: 6.8 Medium
Published: Jun 12, 2026
Updated: Jun 12, 2026
Reserved: May 12, 2026

Description

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, Netty's DNS resolver uses a predictable PRNG for generating DNS transaction IDs and defaults to a static UDP source port. This combination reduces the entropy of DNS queries, enabling DNS Cache Poisoning (Kaminsky attack). Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Scores

CVSS	Score	Vector	Source
3.1	6.8 Medium	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N	GitHub_M

Weaknesses

CWE-330 Use of Insufficiently Random Values
CWE-340 Generation of Predictable Numbers or Identifiers

Affected Products

Product	Versions
nettynetty	>= 4.2.0.Final, < 4.2.15.FinalAffected < 4.1.135.FinalAffected

References

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