Quick answers
- Is CVE-2026-83989 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-83989 being exploited in the wild.
- How severe is CVE-2026-83989?
- High severity, with a CVSS score of 7.5, published 8 September 2026.
- Which products and versions are affected?
- Microsoft Windows Services for NFS <UNKNOWN>.
- Is there a fix for CVE-2026-83989?
- 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-2026-83989 attacked?
- It is attacked over the network, in an operating system.
- Am I affected by CVE-2026-83989?
- Check whether you run Microsoft Windows Services for NFS at an affected version. 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
The vulnerability is an out-of-bounds read in the ONCRPC XDR (External Data Representation) driver component of Windows Services for NFS. The flaw allows an unauthenticated remote attacker to send specially crafted network packets to trigger the out-of-bounds read, resulting in a denial-of-service condition. No user interaction or prior authentication is required; the vulnerability is network-accessible. An attacker can exploit this to cause the NFS service to crash or become unresponsive. A patch is available from Microsoft.
Affected products
- Microsoft Windows Services for NFS <UNKNOWN>
Timeline
- 2026-09-08: disclosed