Quick answers
- Is CVE-2026-40670 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-40670 being exploited in the wild.
- How severe is CVE-2026-40670?
- Informational severity, published 10 November 2026.
- Which products and versions are affected?
- AMD Secure Encrypted Virtualization - Secure Nested Paging.
- Is there a fix for CVE-2026-40670?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-40670 attacked?
- It is attacked from the adjacent network, in device firmware.
- Am I affected by CVE-2026-40670?
- Check whether you run Amd Secure Encrypted Virtualization - Secure Nested Paging. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
An improper check for exceptional conditions in SEV-SNP's handling of MMIO region configuration allows insufficient validation when mapping MMIO address ranges. A privileged attacker with hypervisor access can exploit this to create overlapping MMIO and DRAM region mappings, bypassing memory isolation guarantees and potentially corrupting or accessing guest VM data.
Affected products
- AMD Secure Encrypted Virtualization - Secure Nested Paging
Timeline
- 2026-11-10: disclosed