CVE-2026-20786

Executive Summary

CVE-2026-20786 is an out-of-bounds read (CWE-125) vulnerability in the Intel(R) NPU (Neural Processing Unit) Driver affecting all versions. A local, unprivileged, authenticated user can trigger a denial-of-service condition against the NPU driver by exploiting a low-complexity flaw that requires no user interaction and no special internal knowledge. The vulnerability is reached from Ring 3 (user applications) via local access, and its primary impact is high availability loss (system or driver crash), with low integrity impact and no confidentiality impact. As of this report, no vendor patch has been identified, no CISA KEV listing exists, and no public exploit code has been confirmed; detection and mitigation must therefore rely on host-based monitoring and access hardening.

Technical Analysis

The NVD description identifies the flaw as an out-of-bounds read (CWE-125) in the Intel(R) NPU Driver, reachable by user-mode (Ring 3) applications. The NPU is a dedicated AI-inference accelerator integrated into modern Intel client platforms; its driver exposes a device interface that privileged kernel components use to service requests from user-space applications (e.g., AI/ML runtimes, media pipelines). The vulnerability class indicates that the driver performs a memory read using a length, offset, or index value that is not properly validated against the actual bounds of an allocated buffer or data structure.

The attack surface is the driver's user-mode-facing interface. An authenticated user without elevated privileges can open the relevant device handle and issue control operations that pass buffer descriptors, size fields, or element counts to the driver. If the driver trusts these values without sufficient validation, a crafted request can cause the driver to read past the end of an internal buffer. The resulting access violation typically manifests as a fault in kernel or driver context, leading to a system crash (blue screen on Windows, kernel oops/panic on Linux) or a hang of the NPU subsystem — i.e., a denial of service.

Key characteristics from the NVD description:

• Reachability: Ring 3 (user applications), local access only.
• Preconditions: authenticated user; no user interaction; no special internal knowledge ("attack requirements are not present").
• Complexity: low.
• Impact allocation (driver level): confidentiality none, integrity low, availability high.
• System-level follow-on impact: confidentiality none, integrity none, availability none — meaning the DoS does not pivot into data theft or system compromise beyond availability loss.

The attacker does not need kernel privileges, physical access, or social engineering. Any locally logged-in user (including a guest or low-privileged service account) who can reach the NPU driver interface can repeatedly attempt the malformed operation. The "all versions" statement in the NVD description, combined with patch confidence 0/4, suggests the flaw exists across the full driver lineage and no fix has been observed in any tracked source.

Insufficient technical detail is available in the NVD description to identify the specific ioctl, device node, buffer type, or function name. The analysis above is therefore intentionally at the vulnerability-class level.

Exploitation Scenarios

No public PoC or exploit code has been confirmed for CVE-2026-20786. The attack chain below is inferred strictly from the NVD description and the CWE-125 vulnerability class.

1. Reconnaissance / target identification: The adversary first gains a foothold on the target host as an unprivileged, authenticated user (e.g., via compromised credentials, a low-privilege application, or an existing user account). They then enumerate the system for an accessible Intel NPU driver interface. On typical deployments, the NPU driver exposes a device node or character device accessible from user space; the attacker checks whether the device is present and whether they have the required permissions to open it.

2. Flaw trigger: The adversary issues a driver operation that includes a size, length, offset, or count parameter describing a buffer that is smaller than the driver expects, or requests a read using an out-of-range index/length. Because the driver lacks sufficient bounds validation (CWE-125), the out-of-bounds read is performed against kernel/driver memory adjacent to the intended buffer.

3. Payload / execution method: At the vulnerability-class level, the payload is a malformed request structure — typically a buffer descriptor with an inflated length field or a negative/oversized offset — passed through the driver's user-mode interface. No user interaction is required; the malicious call can be made from a simple compiled executable, a script invoking a driver API, or a crafted IPC message, all running at Ring 3. Low complexity means the attacker does not need to defeat mitigations such as KASLR, SMEP, or SMAP; they only need to induce an invalid memory read.

4. Post-exploitation impact: The out-of-bounds read triggers a fault in the driver, causing the NPU driver to crash or the operating system to enter a bug-check/panic state. The outcome is a denial of service: the NPU becomes unavailable for AI workloads, the affected service terminates, or the entire system reboots. Per the CVSS-style impact data, the attacker gains no confidentiality benefit from the read (confidentiality: none) and does not escalate to kernel code execution; the integrity impact is limited to low, consistent with state corruption that may accompany the fault. The primary business effect is availability loss.

Impact Assessment

• Business impact: Any organization deploying Intel client platforms with an active NPU driver (e.g., AI-accelerated laptops, edge workstations, thin clients running local inference workloads) is exposed. A single unprivileged user can crash shared multi-user systems or dedicated AI workstations, causing productivity loss and interrupting ML inference pipelines. In virtualized or high-availability environments, repeated exploitation can force cascading failovers.
• Affected systems: Systems with the Intel(R) NPU Driver installed — the NVD description states "all versions," so no known version is exempt. The exact OS and platform matrix (Windows/Linux, Meteor Lake and successor cores) cannot be confirmed from the data provided.
• Blast radius: Local only. The vulnerability does not enable remote exploitation, network propagation, data exfiltration, or privilege escalation. The system-level impact vector is limited to availability (DoS); confidentiality and integrity impacts at the system level are none. However, because the precondition is merely an authenticated local user, the effective blast radius is any environment with multi-user access to NPU-equipped hardware.
• Severity context: CVSS score is N/A in the source data; the qualitative profile (AV:L / AC:L / PR:L / UI:N, C:N/I:L/A:H) maps to a high-impact local availability issue. The EPSS score of 0.00143 (4.1% percentile) indicates a very low current probability of exploitation in the wild, consistent with the absence of public PoC and CISA KEV listing.

Detection Guidance

The attack is local and does not generate distinctive network traffic. Detection must therefore focus on host telemetry: driver faults, unexpected reboots, crash dumps, and abnormal repeated access to NPU device interfaces from low-privileged processes. The rules below are heuristic baselines and should be tuned to the observed baseline of the environment.

Sigma Rule

title: Intel NPU Driver Out-of-Bounds Read Denial of Service Activity
id: 5c0d8f2a-1b4e-4c7a-9e2b-8d3f6a1c9e07
status: experimental
description: Detects repeated system crash or driver fault events referencing the Intel NPU driver, consistent with CVE-2026-20786 local DoS attempts.
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2026-20786
tags:
    - attack.impact
    - attack.t1499
logsource:
    product: windows
    service: system
detection:
    selection_crash:
        EventID:
            - 1001    # Windows Error Reporting / BugCheck
            - 41      # Kernel-Power (unexpected shutdown)
            - 7034    # Service terminated unexpectedly
    selection_npu:
        Message|contains|all:
            - 'npu'
            - 'driver'
    condition: selection_crash and selection_npu
    timeframe: 10m
level: high
falsepositives:
    - Legitimate NPU driver crashes due to faulty hardware or outdated firmware
    - Vendor diagnostic tools that intentionally fault the driver

YARA Rule

rule intel_npu_driver_oob_read_indicators
{
    meta:
        author = "ValtersIT Threat Intelligence"
        description = "Heuristic detection of binaries or crash artifacts referencing the Intel(R) NPU Driver, potentially related to CVE-2026-20786"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-20786"
        cwe = "CWE-125"
        date = "2026-01-01"
        severity = "medium"

    strings:
        $s1 = "Intel(R) NPU Driver" ascii wide
        $s2 = "npu" ascii wide nocase
        $s3 = "NPU" ascii wide
        $pe = { 50 45 00 00 }          // PE signature

    condition:
        uint16(0) == 0x5A4D and $pe at pe.entry_point and 1 of ($s*)
}

Note: This rule is intentionally generic because the NVD description does not expose device names, API names, or string constants. It will match any PE, script, or crash dump containing "NPU" references and should be used as a triage filter rather than a definitive exploit indicator.

Suricata IDS Rule

Network detection is of limited value for a local-access vulnerability. The following rule monitors for anomalous outbound crash-report beaconing from a host that has experienced NPU driver faults; it should be deployed only where crash-report exfiltration (e.g., Windows Error Reporting) is considered a monitoring signal.

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2026-20786 - Repeated crash-report upload activity from Intel NPU host"; flow:to_server,established; content:"POST"; http_method; threshold:type both, track by_src, count 5, seconds 600; classtype:attempted-dos; sid:2026207861; rev:1;)

Operators should treat this rule as informational; for authoritative detection of CVE-2026-20786, rely on host-based crash event monitoring (Sigma/Elastic/Splunk/Wazuh rules above).

Elastic Detection

sequence by host.name with maxspan=15m
  [ any where event.code == "1001" and winlog.provider_name == "Microsoft-Windows-WER-SystemErrorReporting"
      and message like "*npu*" ]
  [ any where event.code == "1001" and winlog.provider_name == "Microsoft-Windows-WER-SystemErrorReporting"
      and message like "*npu*" ]

This EQL sequence flags hosts that generate two or more NPU-related Windows Error Reporting (BugCheck) events within 15 minutes, which is consistent with a low-complexity DoS attempt being replayed until system failure.

Splunk SPL Query

index=windows source="XmlWinEventLog:System"
| search EventCode=1001 OR EventCode=41
| where match(Message, "(?i)npu") OR match(Message, "(?i)driver")
| stats count by host, EventCode, Message
| where count >= 2
| sort - count
| rename count as "CrashEventCount", host as "Endpoint"
| table Endpoint, EventCode, CrashEventCount, Message

This query identifies endpoints with repeated NPU/driver-related crash events, the strongest host-side signal for this local DoS vulnerability. Adjust the message filter to the actual Windows event log localization in use.

Wazuh OSSEC Rule

<group name="windows,system_events,intel_npu_driver,">
  <rule id="100207" level="12" frequency="3" timeframe="300">
    <if_matched_sid>18103, 18104</if_matched_sid>
    <field name="win.system.eventID">^1001$</field>
    <match>npu|NPU</match>
    <description>CVE-2026-20786: Repeated Intel NPU driver fault events indicating possible out-of-bounds read DoS attempts.</description>
    <group>attack.t1499,</group>
  </rule>
</group>

This Wazuh rule correlates multiple Windows Error Reporting events (Event ID 1001) containing NPU references within a 5-minute window and raises a high-severity alert.

Mitigation & Patch Guidance

Patch confidence: 0/4 — UNPATCHED. No patch evidence was found in any tracked source, no vendor fix is available, and no official workarounds have been published. The following steps are therefore layered, risk-reducing measures; they do not eliminate the underlying flaw.

1. Immediate mitigations:

   • Restrict access to the NPU driver interface. On multi-user systems, ensure only trusted administrator/operator accounts can open the NPU device node, and deny access to unprivileged or guest accounts via ACLs/device permissions where the OS permits.
   • Disable or unbind the NPU device on systems that do not actively use AI/ML acceleration, reducing the attack surface to zero for those hosts.
   • Monitor all endpoints with the Intel(R) NPU Driver for abnormal crash rates and repeated reboot events; escalate any host generating multiple NPU-related BugCheck/panic events within a short window.
   • Segment or restrict multi-user access to NPU-equipped systems (e.g., dedicated AI workstations) so that unprivileged authenticated users cannot interact with the affected driver.

2. Patch / upgrade steps:

   • Track Intel Security Center advisories and the NVD entry for CVE-2026-20786; no patched driver version has been released or confirmed as of this report.
   • When an updated Intel NPU Driver is published, test it first in a staging environment that mirrors production hardware, then deploy via the standard software management toolchain (SCCM, Intune, WSUS, etc.).
   • Verify the updated driver version against all affected platforms before broad deployment, since the NVD description states "all versions" are affected.

3. Long-term hardening:

   • Apply the principle of least privilege to all locally interactive accounts; the vulnerability requires no privileges beyond authentication, so reducing the number of authenticated users on NPU-equipped hosts proportionally reduces exposure.
   • Enable and centrally collect Windows Error Reporting, kernel crash dumps, and Linux kernel oops/panic logs; retain them for forensic correlation when DoS events occur.
   • Keep the OS and all hardware drivers current, and subscribe to Intel's security advisory feed for future patches.
   • Consider hardware rotation or isolation for NPU workloads in high-security enclaves until a fix is available, and document the residual risk in the system risk register.

References

1. NVD Entry — https://nvd.nist.gov/vuln/detail/CVE-2026-20786
2. Intel Security Center (advisory tracking for Intel products) — https://www.intel.com/content/www/us/en/security-center/default.html
3. MITRE CWE-125 (Out-of-bounds Read) — https://cwe.mitre.org/data/definitions/125.html
4. FIRST EPSS (CVE-2026-20786 score context) — https://www.first.org/epss/
5. CISA Known Exploited Vulnerabilities Catalog — https://www.cisa.gov/known-exploited-vulnerabilities-catalog (CVE-2026-20786 is NOT listed; no exploit-in-the-wild evidence)

No known threat-actor campaigns or in-the-wild exploitation have been associated with CVE-2026-20786 as of the date of this report.