CVE-2026-56444: Degradation of resolution service when 'discard-timeout' and 'serve-expired-client-timeout' are combined in unusual configuration

mediumCVSS 5.9CVE-2026-56444

CSIRTS triage

vendor: null product: nullOther

What: Degradation of resolution service occurs with unusual configurations of 'discard-timeout' and 'serve-expired-client-timeout'.
Who is affected: Systems with specific DNS configurations are affected.
Urgency: Remediation is medium urgency as it may impact service reliability.
Action: Review and adjust DNS configurations accordingly.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 5.9
Published: 2026-07-14
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56444

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-564440.24% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 15% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-56444	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for Degradation of resolution

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

lowCVE-2026-41637: Degradation of resolution service from improperly accounted client-terminated DNS-over-QUIC qu…msrc · 2026-07-14