CVE-2026-42255

CVE-2026-42255 is a high-severity vulnerability in Technitium Dnsserver with a CVSS 3.x base score of 7.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-684.

Key facts

Description

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

Frequently asked questions

What is CVE-2026-42255?
Technitium DNS Server before 15.0 allows DNS traffic amplification via cyclic name server delegation.
How severe is CVE-2026-42255?
CVE-2026-42255 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.
Is CVE-2026-42255 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-42255?
CVE-2026-42255 affects Technitium Dnsserver. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-42255?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-42255 have an EU (EUVD) identifier?
Yes. CVE-2026-42255 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-25688.
When was CVE-2026-42255 published?
CVE-2026-42255 was published on 2026-04-26 and last updated on 2026-06-17.

References

Affected products (1)

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