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Vulnerabilities

Vulnerability · CVE-2026-12855

VU#553437: InsydeH2O IHISI SMM is vulnerable to unsafe memory write operations

Published Oct 1, 2026 · CERT/CC

Check if you run it

No confirmed exploitation is on record for CVE-2026-12855. EPSS is 0.13%. Act only if a listed version of CERT/CC is installed.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.13%
Remediation
Not established
Affected products
CERT/CC

Overview An Out-of-bounds Write vulnerability in the InsydeH2O IHISI software used by HP PC BIOS can allow a local attacker with OS kernel privileges to perform arbitrary physical memory writes, including writes to System Management RAM (SMRAM). Because the vulnerable code executes in System Management Mode (SMM), successful exploitation can allow an attacker to modify SMM-protected memory and potentially achieve arbitrary code execution in SMM. Depending on the platform's memory and firmware configuration, the arbitrary physical memory write primitive may also have i

No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.

How to fix CVE-2026-12855

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-12855. EPSS is 0.13%. Act only if a listed version of CERT/CC is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.13%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 1, 2026 · CERT/CC Vulnerability Notes

    Detected

    Overview An Out-of-bounds Write vulnerability in the InsydeH2O IHISI software used by HP PC BIOS can allow a local attacker with OS kernel privileges to perform arbitrary physical memory writes, including writes to System Management RAM (SMRAM). Because the vulnerable code executes in System Management Mode (SMM), successful exploitation can allow an attacker to modify SMM-protected memory and pot

Sources

  • CERT/CC Vulnerability NotesGovernment advisoryCVE-2026-12855

    Overview An Out-of-bounds Write vulnerability in the InsydeH2O IHISI software used by HP PC BIOS can allow a local attacker with OS kernel privileges to perform arbitrary physical memory writes, including writes to System Management RAM (SMRAM). Because the vulnerable code execut

    kb.cert.org
  • CVE.orgVulnerability recordCVE-2026-12855

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-12855

    30-day exploitation probability 0.1%

    first.org

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.