SecOps SignalSecurity Intelligence Workspace
Loading collection status
Vulnerabilities/CVE-2026-97631Public Intelligence Dossier
Source: Microsoft · Limited verification•Last verified: •Collection Degraded
CVE-2026-97631Unknown / EvaluatingImportant (raw)CVSS 9.5CWE-120

Pre-boot RCE in EDK II PXE driver

Published: 31 Oct 2026•Last updated: 01 Nov 2026, 08:35 PM IST•Source identifier: infosec@edk2.groups.io
Dossier completeness: source-provided sections 3 / 3 · rule guidance available. Missing source facts count as incomplete.
Official source
CISA KEV catalog
Unknown
KEV status was not determined.
CVSS score
9.5Important (raw)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Metric sourceinfosec@edk2.groups.io
EPSS probability
0.6%0.006
Percentile50th
Weakness type
CWE-120
CWE-131, CWE-787
Remediation
Patch status unknown
No fixed version or KB recorded

Why It Matters

Analysis dossier

Why It Matters

EDK2 contains a vulnerability in BIOS where a user may cause “Out-of-bounds Write”, Classic Buffer Overflow, and “Incorrect Calculation of Buffer Size” by remote access. Successful exploitation of this vulnerability can lead to arbitrary code execution. It could also impact Confidentiality, Integrity, and Availability.

SOC priority

High Severity / Review

Actively exploited (source statement)

Unknown

Publicly disclosed

Unknown

Risk basis: Microsoft or Microsoft-managed product relevance; CRITICAL severity; Critical source severity without confirmed exploitation

Affected Products & Remediation

4 source-backed products
Affected products and versions (source)
  • azl3 edk2 20240524git3e722403cd16-21 on Azure Linux 3.0 · version range not provided by source · Microsoft MSRC · Source
  • azl3 qemu 10.1.0-2 on Azure Linux 3.0 · version range not provided by source · Microsoft MSRC · Source
  • azl3 edk2 20240524git3e722403cd16-20 on Azure Linux 3.0 · version range not provided by source · Microsoft MSRC · Source
  • azl3 qemu 10.1.0-1 on Azure Linux 3.0 · version range not provided by source · Microsoft MSRC · Source
Recorded patch / KBNot provided by source

Vendor or catalog guidance (source)

  • Microsoft MSRC: Release Notes

Known exploitation (source facts)

Only what a source states. Unknown means no source has said either way; it is not "not exploited".

CISA KEV
Unknown
Exploited (source statement)
Unknown
Publicly disclosed (source)
Unknown

Suggested hunting (rule-based inference)

SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.

Matched network-unauthenticated (CVSS AV:N, CVSS PR:N, CVSS UI:N)

Exposure

  1. Identify devices reporting this CVE and note which expose the affected service to untrusted networks.Telemetry: DeviceTvmSoftwareVulnerabilities · A network-reachable, no-privilege vector makes internet-facing instances the first exposure question. · Rule network-unauthenticated

Exploitation evidence

  1. Review inbound connections to the affected service from unexpected sources since the advisory date.Telemetry: DeviceNetworkEvents · Hunting hypothesis from the CVSS vector; it does not show that exploitation occurred. · Rule network-unauthenticated

Response

  1. Confirm the source-stated update is installed and the CVE is no longer reported.Telemetry: DeviceTvmSoftwareVulnerabilities · A follow-up inventory check verifies remediation. · Rule network-unauthenticated

CISA KEV Record

CISA KEV status was not determined for this record.

Change History & Source Data

— No recorded material change

CNA / source
infosec@edk2.groups.io
Record status · verification
UPDATED · Unknown
CPE
Unknown

Evidence & Provenance

3 public sources
api.msrc.microsoft.comSource recordnvd.nist.govSource recordgithub.comSource record

Linked by the query's stored exact CVE association. Review required tables and validation status before use.

Detection Hunting Query
Target: DeviceTvmSoftwareVulnerabilities•Defender XDR
Detect endpoints exposed to CVE-2026-97631
Purpose: Exposure assessment (Category: Exposure Check)Why linked: Query metadata names CVE-2026-97631
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2026-97631"| project DeviceId, DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, RecommendedSecurityUpdateId| sort by VulnerabilitySeverityLevel desc
Schema Checked · Not runtime validatedSource: SecOps Signal deterministic template · Limited verificationStatic screening: Passed structure and schema checks; tenant execution is not verified.
Open KQL Library

Looking up related community queries…

Loading related intelligence

Correlated briefings

SecOps Signal surfaces public advisory facts only. A missing value means the source has not published it, not that your environment is unaffected. No tenant inventory is connected.