CVE-2026-40670AMD EPYC™ 9004 Series Processors unchecked unusual condition
CVE-2026-40670 is a unchecked unusual condition in AMD EPYC™ 9004 Series Processors, rated medium (5.9 on CVSS 4.0).
Why this priority: Medium severity, with no exploitation signal.
Published · Updated · NVD status: Received
What it is
An unusual condition is not handled, leaving the software in an unsafe state.
How it is reached
An attacker can exploit it by someone who can already run code or sign in on the machine, with an administrator account, and nobody has to click anything.
What an attacker gains
The scored direct impact on the component itself is low. In practice, this kind of flaw lets an attacker drive the component into behaviour its authors did not intend. The damage can spread past the vulnerable component into others.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- No fixed version is listed yet. Find every place AMD EPYC™ 9004 Series Processors runs, watch the references for a fix, and plan a replacement if it is no longer supported.
- Limit who can run code or sign in on the hosts that run it.
Description from NVD
Improper check for unusual or exceptional conditions in AMD Secure Encrypted Virtualization - Secure Nested Paging (SEV-SNP) could allow a privileged attacker to potentially overlap MMIO regions with DRAM regions resulting in loss of integrity.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Interfaces that accept external input. The flaw sits at the input boundary of the affected component.
Trust boundaries in play
- Host boundary. The attacker needs a foothold on the machine first; the flaw turns a small foothold into a bigger one.
- Isolation between components. The impact crosses out of the vulnerable component into others it should be isolated from.
- At the input boundary of the affected component. An attacker who crosses it can drive the component into behaviour its authors did not intend.
Questions to answer about your own systems
- Where does AMD EPYC™ 9004 Series Processors run in your systems, and at which version?
- Which of those hosts also run code or users you do not fully trust?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.