Affects Microsoft Active Directory Domain Services (widely deployed domain controllers). Unauthenticated RCE against DCs can lead to full domain compromise and widespread enterprise disruption.
CVE-2026-49164
Heap overflow in Active Directory DS enabling remote code execution on domain controllers.
Is CVE-2026-49164 being exploited?
Not confirmed. CVE-2026-49164 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 0.79% probability of exploitation in the next 30 days.
How severe is CVE-2026-49164?
CVE-2026-49164 is rated High with a CVSS score of 8.1. 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-2026-49164?
Yes. A fix has been recorded for CVE-2026-49164. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-49164 affect?
CVE-2026-49164 affects Microsoft Active Directory Domain Services, Windows Server Domain Controllers. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-49164?
Isolate DCs, enforce segmentation, enable EDR/IDS, monitor logs; apply vendor patch immediately when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated remote code execution on domain controllers via heap buffer overflow; may enable full domain takeover.
Immediate action required
- affected>= 10.0.14393.0 and < 10.0.14393.9339
- affected>= 10.0.17763.0 and < 10.0.17763.9020
- affected>= 10.0.19044.0 and < 10.0.19044.7548
- affected>= 10.0.19045.0 and < 10.0.19045.7548
- affected>= 10.0.26100.0 and < 10.0.26100.8875
- affected>= 10.0.26200.0 and < 10.0.26200.8875
- affected>= 10.0.28000.0 and < 10.0.28000.2525
- affected>= 6.2.9200.0 and < 6.2.9200.26226
- affected>= 6.3.9600.0 and < 6.3.9600.23291
- affected>= 6.3.9600.0 and < 6.3.9600.23291
- affected>= 6.2.9200.0 and < 6.2.9200.26226
- affected>= 10.0.14393.0 and < 10.0.14393.9339
- affected>= 10.0.14393.0 and < 10.0.14393.9339
- affected>= 10.0.17763.0 and < 10.0.17763.9020
- affected>= 10.0.17763.0 and < 10.0.17763.9020
- affected>= 10.0.20348.0 and < 10.0.20348.5386
- affected>= 10.0.26100.0 and < 10.0.26100.33158
- affected>= 10.0.26100.0 and < 10.0.26100.33158
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.