CVE-2026-55973: 'dns-error-reporting: yes' leads to stack buffer overflow

highCVSS 7.5CVE-2026-55973

CSIRTS triage

vendor: CoreDNS product: CoreDNS Memory corruption

What: 'dns-error-reporting: yes' leads to a stack buffer overflow.
Who is affected: Deployments of CoreDNS with dns-error-reporting enabled.
Urgency: Remediation is high urgency due to the high severity and potential for exploitation.
Action: Patch to the latest version to resolve the vulnerability.

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: high — CVSS 7.5
Published: 2026-07-14
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55973

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-2026-559730.29% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 21% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-55973	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 'dns-error-reporting

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.

highCVE-2026-55973: In NLnet Labs Unbound 1.23.0 up to and including 1.25.1, when 'dns-error-reporting: yes' is se…nvd · 2026-07-22