CVE-2026-50252: Possible cache poisoning attack by mapping source port population per thread

CSIRTS triage

What

A possible cache poisoning attack can occur by mapping source port population per thread.

Who is affected

Deployments using affected DNS services are at risk.

Urgency

Remediation is low priority due to the unknown severity of the vulnerability.

Action

Monitor for updates and apply them when convenient.

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

Details

Source

Microsoft Security Response Center (INTL · vendor-psirt · site)

Severity

unknown

Published

2026-07-14

Exploitation

Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50252

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-2026-502520.14% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all scored CVEs.

Referenced CVEs

Same CVEs, other sources

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

• medium[NEW] [medium] Unbound: Multiple vulnerabilitiescert-bund
• criticalCVE-2026-50252: In NLnet Labs Unbound 1.4.22 up to and including 1.25.1, UDP source port is randomized and int…nvd

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