Affects Microsoft Active Directory Domain Services — ubiquitous enterprise service; remote code execution on AD Controllers risks full domain compromise.
CVE-2026-49178
Heap overflow in Active Directory Domain Services enabling remote code execution.
Is CVE-2026-49178 being exploited?
Not confirmed. CVE-2026-49178 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 0.91% probability of exploitation in the next 30 days.
How severe is CVE-2026-49178?
CVE-2026-49178 is rated High with a CVSS score of 8.8. 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-2026-49178?
Yes. A fix has been recorded for CVE-2026-49178. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-49178 affect?
CVE-2026-49178 affects Microsoft Active Directory Domain Services, Windows Server (AD DS hosts/domain controllers). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-49178?
Apply vendor patch when available; restrict AD DS access and monitor domain controllers.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated attacker can trigger a heap overflow in AD DS to execute arbitrary code remotely, potentially gaining SYSTEM and compromising domain controllers.
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.