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High · 8.2 Public exploit CVE-2025-7026 EUVD-2025-21137GHSA-g884-34r9-cwxq

SMM Arbitrary Write via Unchecked RBX Pointer in CommandRcx0

Published Jul 11, 2025 · Updated Feb 26, 2026 · Assigned by certcc

Vendor: GIGABYTE Product: UEFI-GenericComponentSmmEntry

Description

A vulnerability in the Software SMI handler (SwSmiInputValue 0xB2) allows a local attacker to control the RBX register, which is used as an unchecked pointer in the CommandRcx0 function. If the contents at RBX match certain expected values (e.g., '$DB$' or '2DB$'), the function performs arbitrary writes to System Management RAM (SMRAM), leading to potential privilege escalation to System Management Mode (SMM) and persistent firmware compromise.

Affected products

VendorProductAffectedFixed
GIGABYTE UEFI-GenericComponentSmmEntry 1.0.0 —

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

References