CVE-2025-7026
SMM Arbitrary Write via Unchecked RBX Pointer in CommandRcx0
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$'), the function performs arbitrary writes to System Management RAM (SMRAM), leading to potential privilege escalation to System Management Mode (SMM) and persistent firmware compromise.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
SMM Arbitrary Write via Unchecked RBX Pointer in CommandRcx0
A vulnerability in the Software SMI handler (SwSmiInputValue 0xB2) allows a local attacker to control the RBX register, which is used as an unchecked pointer in the CommandRcx0 function. If the contents at RBX match certain expected values (e.g., '$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.
- Record
CVE-2025-7026- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
EUVDEUVD-2025-21137
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$'), the function performs arbitrary writes to System Management RAM (SMRAM), leading to potential privilege escalation to System Management Mode (SMM) and persistent firmware compromise.
- Record
EUVD-2025-21137- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-g884-34r9-cwxq
A vulnerability in the Software SMI handler (SwSmiInputValue 0xB2) allows a local attacker to...
A vulnerability in the Software SMI handler (SwSmiInputValue 0xB2) allows a local attacker to control the RBX register, which is used as an unchecked pointer in the CommandRcx0 function. If the contents at RBX match certain expected values (e.g., '$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.
- Record
GHSA-g884-34r9-cwxq- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-7026- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | Tobss8/GIGABYTE-H510M-K-V2-BIOS-SMM-Reverse-Engineering-CVE-2025-7026-7027-7028-7029-Research | 2026-08-09 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-7026 is a high vulnerability (CVSS 8.2) in Gigabyte Uefi-genericcomponentsmmentry, published July 11, 2025. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 0.23%, the 14th percentile. No source names a fixed version.