AMI AptioV: Buffer access with incorrect length value in BIOS

Summary

AMI AptioV, the UEFI/BIOS firmware used by many mainboard and system manufacturers, contains a flaw in which a local user can trigger a buffer access with an incorrect length value. According to the vendor, successful exploitation could lead to buffer overflows, memory corruption and arbitrary code execution, with impact on confidentiality, integrity and availability. An attacker needs local access and low privileges, so the main risk is a local user account, a malicious insider or a compromised workstation. Because the flaw sits in firmware, a successful attack could persist below the operating system.

Affected

• AMI AptioV, affected versions according to the CVE record: AptioV_5.0 to before AptioV_5.043 (default configuration: unaffected)
• The affected range is disputed: VulDB lists up to 5.42. Unconfirmed; check the AMI advisory and your hardware vendor's bulletin.
• Affected hardware models: depends on the OEM BIOS build. Unknown.

Fixed in

• AptioV 5.043 (AMI core version, according to the CVE record and VulDB)
• OEM-specific BIOS versions per hardware model: Unknown. Obtain them from your hardware vendor.

Workaround

• No vendor-documented workaround known.
• Practical measures (not from a source): restrict local logon and administrator rights, and enable Secure Boot and BIOS write protection where the hardware supports them.

Exploitation

• CISA SSVC assessment: exploitation none, not automatable, total technical impact.
• Not listed as known exploited (CISA KEV).
• No public proof of concept found.
• VulDB labels the entry as "0-Day", which reflects disclosure timing and not confirmed exploitation.

Our recommendation

• Identify all devices with AMI AptioV firmware and check each model against the hardware vendor's security bulletins.
• Install the OEM BIOS update for each affected model as soon as it is available. Several related AMI advisories from the same day may be covered by one update round.
• Limit local access and administrator rights, especially on shared workstations, kiosks and devices with weak local access controls.
• Enable Secure Boot and BIOS write protection where supported.
• Suggested priority: medium-high.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• AMI Security Advisory AMI-SA-2026002 go.ami.com
• VulDB entry 417703 vuldb.com
• Threatint CVE-2025-58774 cve.threatint.com
• Strix CVE-2025-58774 www.strix.ai
• HOL Guard CVE-2025-58774 hol.org
• OpenCVE AMI vendor list app.opencve.io

Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 13:52.