# CVE-2026-83665: Microsoft Windows DHCP Server null pointer dereference

Source: https://junglewise.ai/threats/cve-2026-83665-null-pointer-dereference-in-windows-dhcp-server-allows-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-29  
License: CC BY 4.0 with a link back

CVE-2026-83665 · Severity: high · CVSS 7.5 · Published 2026-10-13

Windows DHCP Server, which assigns network addresses to devices on corporate networks, contains a null pointer dereference vulnerability. An attacker on the network can trigger this flaw to crash the DHCP server, preventing devices from obtaining network addresses and causing a denial of service.

Technologies: [Microsoft Windows DHCP Server](https://junglewise.ai/threats/technologies/windows-dhcp-server), [Microsoft Windows 10 1809](https://junglewise.ai/threats/technologies/windows-10-1809), [Microsoft Windows Server 2012](https://junglewise.ai/threats/technologies/windows-server-2012), [Microsoft Windows Server 2016](https://junglewise.ai/threats/technologies/windows-server-2016), [Microsoft Windows Server 2019](https://junglewise.ai/threats/technologies/windows-server-2019), [Microsoft Windows Server 2022](https://junglewise.ai/threats/technologies/windows-server-2022), [Microsoft Windows Server 2025](https://junglewise.ai/threats/technologies/windows-server-2025). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-83665 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-83665 being exploited in the wild.

**How severe is CVE-2026-83665?** High severity, with a CVSS score of 7.5, published 13 October 2026.

**Which products and versions are affected?** Microsoft Windows DHCP Server.

**Is there a fix for CVE-2026-83665?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-83665 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-83665?** Check whether you run Microsoft Windows DHCP Server, Microsoft Windows 10 1809, Microsoft Windows Server 2012 or one of the others listed. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A null pointer dereference in the Windows DHCP Server process allows an unauthenticated attacker to trigger a crash via a specially crafted network packet. The vulnerability requires network access but no authentication or user interaction. Exploitation results in denial of service through server unavailability.

## Affected products

- Microsoft Windows DHCP Server

## Timeline

- 2026-10-13: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83665](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83665)

## Related threats

- [Microsoft Windows DHCP Server uncontrolled resource consumption](https://junglewise.ai/threats/cve-2026-96134-uncontrolled-resource-consumption-in-windows-dhcp-server-allows)
- [Windows DHCP Server time-of-check time-of-use race condition](https://junglewise.ai/threats/cve-2026-88216-time-of-check-time-of-use-toctou-race-condition-in-windows-dhcp)
- [Microsoft Windows DHCP Server use-after-free remote code execution](https://junglewise.ai/threats/cve-2026-72998-use-after-free-in-windows-dhcp-server-allows-an-unauthorized)
- [Windows DHCP Server out-of-bounds read](https://junglewise.ai/threats/cve-2026-119890-out-of-bounds-read-in-windows-dhcp-server-allows-an-authorized)
- [Microsoft Windows DHCP Server improper access control](https://junglewise.ai/threats/cve-2026-113773-improper-access-control-in-windows-dhcp-server-allows-an)