Description

Buffer over-read in Windows Network File System allows an unauthorized attacker to deny service over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.9",
  "pubDate": "2026-08-11T17:19:06.207Z",
  "pubdate": "2026-08-11T17:19:06.207Z",
  "executiveSummary": "This vulnerability is classified as a buffer over-read affecting the Windows Network File System (NFS).\nThe primary impact of this security flaw is a denial of service (DoS) condition, rendering the affected network file sharing service unresponsive or causing it to crash.\nThe affected product is the Windows Network File System component across applicable operating system versions.\nThe risk implication is service degradation or complete interruption of shared storage resources, impacting availability for dependent clients and enterprise workloads.\nAn unauthorized remote attacker with network access to the target service possesses the capability to trigger this condition.\nExploitation requirements include network connectivity to the listening NFS service without requiring prior authentication or elevated privileges, lowering the barrier for potential threat actors to disrupt critical infrastructure.",
  "technicalDetails": "The vulnerability stems from improper bounds checking within the Windows Network File System component when processing incoming network packets or RPC requests.\nSpecifically, a buffer over-read occurs when the parsing logic reads memory beyond the allocated boundary of an internal buffer due to malformed or maliciously crafted input data supplied by a remote client.\nThe vulnerable component resides within the core NFS network parsing and handling routines responsible for interpreting protocol-specific structures.\nAttack flow begins when an unauthorized attacker transmits a specially crafted network payload targeting the vulnerable NFS service listening on standard network ports.\nUpon receipt, the NFS service attempts to parse the payload, invoking the flawed function that reads past the legitimate data boundary.\nThis out-of-bounds read operation results in memory access violations, triggering an exception that abnormally terminates the service process or corrupts critical internal state, thereby precipitating a denial of service condition.\nNetwork exposure is inherent to the service, as NFS operates over a network stack and is designed to accept incoming connections from remote clients.\nAuthentication requirements are absent, meaning an unauthenticated attacker can initiate the attack sequence directly over the network.\nPrivilege requirements are similarly non-existent; the attacker requires no prior access or credentials within the domain or host operating system to execute the payload.\nPost-exploitation impact is strictly limited to availability loss, manifesting as system crashes, service hangs, and disruption of file input/output operations, without yielding remote code execution or unauthorized data disclosure based on the described over-read behavior."
}