# CVE-2026-83655: Microsoft Network Policy Server out-of-bounds read denial of service

Source: https://junglewise.ai/threats/cve-2026-83655-out-of-bounds-read-in-network-policy-server-nps-allows-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-83655 · Severity: high · CVSS 7.5 · Published 2026-10-13

Network Policy Server (NPS) is a Microsoft service that authenticates and authorizes network access requests. An out-of-bounds read vulnerability allows a remote attacker to crash the service and deny legitimate users access to network resources without requiring credentials or authentication. This could disrupt organizational operations by making network access unavailable.

Technologies: [Microsoft Network Policy Server](https://junglewise.ai/threats/technologies/network-policy-server). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-83655 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-83655 being exploited in the wild.

**How severe is CVE-2026-83655?** High severity, with a CVSS score of 7.5, published 13 October 2026.

**Which products and versions are affected?** Microsoft Network Policy Server.

**Is there a fix for CVE-2026-83655?** 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-2026-83655 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-83655?** Check whether you run Microsoft Network Policy Server. 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

An out-of-bounds read in Network Policy Server results in a denial-of-service condition when triggered by a specially crafted network request. The vulnerability is remotely exploitable over the network without authentication, allowing unauthenticated attackers to trigger the memory access violation and crash the affected service.

## Affected products

- Microsoft Network Policy Server

## Timeline

- 2026-10-13: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83655](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83655)

## Related threats

- [Microsoft Network Policy Server out-of-bounds read](https://junglewise.ai/threats/cve-2026-96246-out-of-bounds-read-in-network-policy-server-nps-allows-an)
- [Microsoft Network Policy Server use-after-free remote code execution](https://junglewise.ai/threats/cve-2026-85811-use-after-free-in-network-policy-server-nps-allows-an)
- [Microsoft Network Policy Server integer underflow remote code execution](https://junglewise.ai/threats/cve-2026-85806-integer-underflow-wrap-or-wraparound-in-network-policy-server-nps)
- [Microsoft Network Policy Server use-after-free remote code execution](https://junglewise.ai/threats/cve-2026-85799-use-after-free-in-network-policy-server-nps-allows-an)
- [Microsoft Network Policy Server use-after-free RCE](https://junglewise.ai/threats/cve-2026-85371-use-after-free-in-network-policy-server-nps-allows-an)