CVE-2025-49666: Microsoft Windows Server 2016 · Heap-based Buffer Overflow
Affects Microsoft Windows Server 2016Source CVE Database V5
Not known to be exploited · CVSS 7.2 High.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 1.4% chance of exploitation in 30 days – higher than 72% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 8 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Windows Server 2016 | Affected
| Fixed in– |
AI-suggested
1. Immediately restrict network access to Windows Server 2016 systems, especially from untrusted networks, using firewalls and network segmentation. 2. Enforce the principle of least privilege by limiting administrative and high-privilege accounts that can access affected servers. 3. Monitor kernel-level events and system logs for unusual activity indicative of exploitation attempts, using advanced endpoint detection and response (EDR) tools. 4. Disable or limit unnecessary network services and protocols on Windows Server 2016 to reduce the attack surface. 5. Prepare for rapid deployment of patches once Microsoft releases an official fix; subscribe to Microsoft security advisories for updates. 6. Conduct vulnerability scanning and penetration testing focused on kernel vulnerabilities to identify exposure. 7. Implement network intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics targeting heap overflow exploitation patterns. 8. Consider upgrading to a supported and patched version of Windows Server where feasible to eliminate exposure. 9. Educate system administrators about the vulnerability and enforce strict change management and access controls. 10. Maintain regular backups and incident response plans to ensure quick recovery in case of compromise.
Description
Heap-based buffer overflow in Windows Kernel allows an authorized attacker to execute code over a network.