Ring 0-to-SMM escalation via LocateProtocol misuse
Published Apr 16, 2026 · Updated Apr 16, 2026
Privilege escalation in AMD processor Platform Initialization firmware allows local users with Ring 0 access to execute code in SMM. The APCB SMM driver's SMI handler incorrectly calls EFI_BOOT_SERVICES.LocateProtocol, exposing a boot service in the privileged SMM context. Exploitation requires existing Ring 0 privileges and high complexity; successful execution crosses into SMM and can compromise system confidentiality, integrity, and availability.
Summary
What happened
Privilege escalation in AMD processor Platform Initialization firmware allows local users with Ring 0 access to execute code in SMM. The APCB SMM driver's SMI handler incorrectly calls EFI_BOOT_SERVICES.LocateProtocol, exposing a boot service in the privileged SMM context. Exploitation requires existing Ring 0 privileges and high complexity; successful execution crosses into SMM and can compromise system confidentiality, integrity, and availability.
The record
- CVE
- CVE-2025-54502
- Published
- Apr 16, 2026
- Updated
- Apr 16, 2026
- Vendor
- Advanced Micro Devices, Inc.
- Product
- AMD Ryzen™ 7000 Series Desktop Processors
- Classifications
- CWE-668, T1068
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Apr 16, 2026CVE publishedPublication date reported by the CVE source.
- Apr 16, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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