Request an audit

// CVE · Published · Lenovo

CVE-2026-105896 · Medium · CVSS 3.1

SMM out-of-bounds write - code execution.

Out-of-bounds write in System Management Mode enabling code execution at SMM (ring -2) by a local privileged attacker.

Published
Vendor
Product
Lenovo BIOS (SMM)
Affected
Lenovo BIOS, 56+ models (Legion, Yoga Pro, IdeaPad Pro, ThinkBook, LOQ)
Fixed in
BIOS updates listed in LEN-220440
Credit
Eva Crystal (0xiviel), XSource Security
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H

Summary

The WmiBiosSetupSmm module in Lenovo BIOS registers a software SMI handler on 0xDE. The handler used the size field of the communication buffer without validating it, so a local administrator could steer an out-of-bounds write from ring 0 into System Management Mode.

Impact

Code execution in SMM, the most privileged mode on the platform. The CVE record reads: “A potential out of bounds write vulnerability could allow a local privileged attacker to execute code in System Management Mode.” Lenovo scores it 6.0 with CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H (CWE-787).

Part of a four-CVE chain

The four Lenovo CVEs describe one handler. CVE-2026-10588 leaks a live SMRAM address through an EFI variable, CVE-2026-10587 and CVE-2026-10589 are the missing buffer validation in the same handler, and CVE-2026-10590 is the missing authentication that lets any ring-0 caller drive it through WMI. Together they take a local administrator from ring 0 to code execution in System Management Mode, below the operating system and below Secure Boot.

The full analysis is in Inside the Lenovo SMM escalation chain, and the disclosure process in Coordinated disclosure with Lenovo PSIRT.

Timeline

  • 8 Mar 2026: report with proof of concept sent to Lenovo PSIRT
  • 11 Mar 2026: acknowledged, tracked as LEN-213632
  • 2 Jun 2026: CVE-2026-10587 to CVE-2026-10590 reserved
  • Jun 2026: fixed BIOS packages released
  • 14 Jul 2026: advisory LEN-220440 published, embargo lifted
  • 16 Jul 2026: CVE records published

Credit

Each CVE record carries the same acknowledgement: “Lenovo thanks 0xiviel/Eva Crystal (XSource Security) for reporting this vulnerability.”

More disclosures

All disclosures →