What is CVE-2026-42255?

CVE-2026-42255 is a high-severity vulnerability in Technitium Dnsserver, classified under CWE-684. CVSS score: 7.2/10. Published 2026-04-26.

How severe is CVE-2026-42255?

High severity. CVSS v3 base score is 7.2 out of 10.

Vulnerability in Technitium Dnsserver

CVE-2026-42255

Technitium DNS Server before 15.0 allows DNS traffic amplification via cyclic name server delegation.

Published 2026-04-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L.

EPSS exploit prediction

EPSS: 0.004 (27.2th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 27.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.001

Affected products

Technitium Dnsserver — versions 0

Weakness classification (CWE)

CWE-684

References

github.com/TechnitiumSoftware/DnsServer/blob/master/CHANGELOG.md (Release Notes)

Frequently asked questions

What is CVE-2026-42255?: CVE-2026-42255 is a high-severity vulnerability in Technitium Dnsserver, classified under CWE-684. CVSS score: 7.2/10. Published 2026-04-26.
How severe is CVE-2026-42255?: High severity. CVSS v3 base score is 7.2 out of 10.