Targets Windows DHCP Server — a widely deployed core network service; RCE can cause broad enterprise disruption and outages.
CVE-2026-88243
Remote code execution via Windows DHCP Server out-of-bounds read.
Is CVE-2026-88243 being exploited?
Not confirmed. CVE-2026-88243 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 1.0% probability of exploitation in the next 30 days.
How severe is CVE-2026-88243?
CVE-2026-88243 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-2026-88243?
Yes. A fix has been recorded for CVE-2026-88243. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-88243 affect?
CVE-2026-88243 affects Windows DHCP Server (Windows Server DHCP service). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-88243?
Apply Microsoft's security update immediately; restrict and isolate DHCP servers from untrusted networks.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attacker can exploit DHCP server OOB read to achieve remote code execution and full system compromise, disrupting network services.
Immediate action required
- 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-2026-88243
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.