Time-of-check time-of-use (toctou) race condition in Microsoft Defender for Endpoint allows an authorized attacker to elevate privileges locally.
Why It Matters
Analysis dossierWhy It Matters
Time-of-check time-of-use (toctou) race condition in Microsoft Defender for Endpoint allows an authorized attacker to elevate privileges locally.
High
Unknown
Unknown
Risk basis: Microsoft or Microsoft-managed product relevance; HIGH severity; Source severity; no confirmed exploitation signal
Affected Products & Remediation
0 source-backed productsVendor or catalog guidance (source)
Not provided by source
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 microsoft-enterprise (Affected product: Defender for Endpoint, Vendor: microsoft); local-access-review (CVSS AV:L, CVSS PR:L)
Exposure
- Identify affected Microsoft products and compare local builds with the MSRC advisory.Telemetry: DeviceTvmSoftwareVulnerabilities · The MSRC product/build mapping establishes applicability. · Rule microsoft-enterprise
- Identify hosts reporting this CVE, prioritising shared or multi-user systems.Telemetry: DeviceTvmSoftwareVulnerabilities · A local, low-privilege vector matters most where untrusted users can run code. · Rule local-access-review
Exploitation evidence
- Review the advisory's documented behavior on matching hosts before selecting a hunt.Telemetry: DeviceProcessEvents · Product family alone does not justify a CVE-specific detection. · Rule microsoft-enterprise
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Exploitation evidence
- Review source-stated impact and relevant application errors on affected hosts; local access alone does not establish privilege escalation.Telemetry: DeviceProcessEvents · The vector establishes local access and low privileges only. Confirm the impact from the advisory before choosing a specific hunt. · Rule local-access-review
Response
- Confirm the source-stated KB or mitigation on matching assets.Telemetry: DeviceTvmSoftwareVulnerabilities · A post-update inventory check verifies remediation. · Rule microsoft-enterprise
CISA KEV Record
CISA KEV status was not determined for this record.
Change History & Source Data
— No recorded material change
- CNA / source
- secure@microsoft.com
- Record status · verification
- UPDATED · Microsoft primary source linked
- CPE
- cpe:2.3:a:microsoft:defender_for_endpoint:*:*:*:*:*:macos:*:*
Evidence & Provenance
Linked by the query's stored exact CVE association. Review required tables and validation status before use.
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2026-56178"| project DeviceId, DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, RecommendedSecurityUpdateId| sort by VulnerabilitySeverityLevel descLooking up related community queries…