{"id":"CVE-2025-7026","aliases":["EUVD-2025-21137","GHSA-g884-34r9-cwxq"],"status":"published","title":"SMM Arbitrary Write via Unchecked RBX Pointer in CommandRcx0","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$'), the function performs arbitrary writes to System Management RAM (SMRAM), leading to potential privilege escalation to System Management Mode (SMM) and persistent firmware compromise.","severity":{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-10","score":0.00234,"percentile":0.14393,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":false},"published":"2025-07-11T15:27:34Z","modified":"2026-06-17T10:04:07Z","exploits":[{"source":"pocgithub","id":"Tobss8/GIGABYTE-H510M-K-V2-BIOS-SMM-Reverse-Engineering-CVE-2025-7026-7027-7028-7029-Research","title":"Tobss8/GIGABYTE-H510M-K-V2-BIOS-SMM-Reverse-Engineering-CVE-2025-7026-7027-7028-7029-Research","date":"2026-08-09","url":"https://github.com/Tobss8/GIGABYTE-H510M-K-V2-BIOS-SMM-Reverse-Engineering-CVE-2025-7026-7027-7028-7029-Research"}],"products":[{"vendor":"gigabyte","product":"uefi-genericcomponentsmmentry"}],"references":[{"url":"https://www.gigabyte.com/Support/Security"},{"url":"https://www.binarly.io/advisories/brly-dva-2025-008"},{"url":"https://kb.cert.org/vuls/id/746790"},{"url":"https://www.kb.cert.org/vuls/id/746790"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-7026"},{"url":"https://github.com/advisories/GHSA-g884-34r9-cwxq"}],"sources":{"cve":[{"id":"CVE-2025-7026","title":"SMM Arbitrary Write via Unchecked RBX Pointer in CommandRcx0","description":"A vulnerability in the Software SMI handler (SwSmiInputValue 0xB2) allows a local attacker to control the RBX register, which is used as an unchecked pointer in the CommandRcx0 function. If the contents at RBX match certain expected values (e.g., '$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.","status":"published","published":"2025-07-11T15:27:34.96Z","modified":"2026-02-26T17:50:43.39Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"adp"}],"updated_at":"2026-11-02T14:32:51.544289Z"}],"euvd":[{"id":"EUVD-2025-21137","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$'), the function performs arbitrary writes to System Management RAM (SMRAM), leading to potential privilege escalation to System Management Mode (SMM) and persistent firmware compromise.","status":"published","published":"2025-07-11T15:27:34Z","modified":"2026-02-26T17:50:43Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T19:48:19.036418Z"}],"ghsa":[{"id":"GHSA-g884-34r9-cwxq","title":"A vulnerability in the Software SMI handler (SwSmiInputValue 0xB2) allows a local attacker to...","description":"A vulnerability in the Software SMI handler (SwSmiInputValue 0xB2) allows a local attacker to control the RBX register, which is used as an unchecked pointer in the CommandRcx0 function. If the contents at RBX match certain expected values (e.g., '$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.","status":"published","published":"2025-07-11T18:30:34Z","modified":"2025-11-03T21:35:13Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:04:25.4654Z"}],"nvd":[{"id":"CVE-2025-7026","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.","status":"published","published":"2025-07-11T16:15:26.897Z","modified":"2026-06-17T10:04:07.337Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"updated_at":"2026-11-02T14:11:18.285862Z"}]}}