Remote RCE in Microsoft Windows DNS impacts widely deployed Windows Server infrastructure; urgent mass remediation required.
CVE-2026-88218
Remote code execution via double-free in Windows DNS service
Is CVE-2026-88218 being exploited?
Not confirmed. CVE-2026-88218 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 1.1% probability of exploitation in the next 30 days.
How severe is CVE-2026-88218?
CVE-2026-88218 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-88218?
Yes. A fix has been recorded for CVE-2026-88218. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-88218 affect?
CVE-2026-88218 affects Microsoft Windows DNS service (dns.exe), Windows Server with DNS role, Domain controllers running DNS. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-88218?
Apply Microsoft's security update immediately; prioritize DNS servers and domain controllers.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attackers can execute arbitrary code as SYSTEM via crafted DNS requests, enabling server compromise and lateral movement.
Immediate action required
- affected>= 10.0.14393.0 and < 10.0.14393.9688
- affected>= 10.0.17763.0 and < 10.0.17763.9487
- affected>= 10.0.19044.0 and < 10.0.19044.7846
- affected>= 10.0.19045.0 and < 10.0.19045.7846
- affected>= 10.0.22631.0 and < 10.0.22631.7711
- affected>= 10.0.22631.0 and < 10.0.22631.7711
- affected>= 10.0.26100.0 and < 10.0.26100.9974
- affected>= 10.0.26200.0 and < 10.0.26200.9974
- affected>= 10.0.28000.0 and < 10.0.28000.3501
- affected>= 10.0.26300.0 and < 10.0.26300.9974
- affected>= 10.0.14393.0 and < 10.0.14393.9688
- affected>= 10.0.14393.0 and < 10.0.14393.9688
- affected>= 10.0.17763.0 and < 10.0.17763.9487
- affected>= 10.0.17763.0 and < 10.0.17763.9487
- affected>= 10.0.20348.0 and < 10.0.20348.5870
- affected>= 10.0.26100.0 and < 10.0.26100.33822
- affected>= 10.0.26100.0 and < 10.0.26100.33822
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
cisa ssvc
- exploitation
- none
- automatable
- yes
- technical impact
- total
Assessed by CISA 5 Nov 2026 (SSVC 2.0.3).
timeline
- 5 Nov 2026CISA SSVC assessment: exploitation none
- 10 Nov 2026Published · 6 days later
- 11 Nov 2026CVE record last updated · 1 day later
- 12 Nov 2026Analysed by vulneraibility.com · 1 day later
- Patchmsrc.microsoft.com /update-guide/vulnerability/CVE-2026-88218
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.