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PatchSiren cyber security CVE debrief

CVE-2026-45673 netty CVE debrief

CVE-2026-45673 is a DNS Cache Poisoning vulnerability in Netty, a network application framework. The vulnerability has a CVSS score of 6.8 and was published on 2026-06-12T15:16:27.417Z. The vulnerability exists in Netty's DNS resolver, which 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). The vulnerability was patched in versions 4.1.135.Final and 4.2.15.Final.

Vendor
netty
Product
Unknown
CVSS
MEDIUM 6.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-12
Original CVE updated
2026-06-15
Advisory published
2026-06-12
Advisory updated
2026-06-15

Who should care

Users of Netty versions prior to 4.1.135.Final and 4.2.15.Final should update to a patched version to prevent DNS Cache Poisoning attacks.

Technical summary

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).

Defensive priority

High

Recommended defensive actions

  • Update to Netty version 4.1.135.Final or 4.2.15.Final or later.
  • Use a secure PRNG for generating DNS transaction IDs.
  • Use a random UDP source port for DNS queries.

Evidence notes

The vulnerability was patched in versions 4.1.135.Final and 4.2.15.Final. [ref-4](https://github.com/netty/netty/releases/tag/netty-4.1.135.Final), [ref-5](https://github.com/netty/netty/releases/tag/netty-4.2.15.Final), [ref-6](https://github.com/netty/netty/security/advisories/GHSA-xmv7-r254-6q78)

Sources and references

Verified primary and authoritative sources

  • CVE-2026-45673 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-45673

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-45673 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-45673

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.