CASCACascade Atlas

Evidence dossier

CVE-2026-41091

Microsoft Defender Elevation of Privilege Vulnerability

65.3–80.3Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

Improper link resolution before file access ('link following') in Microsoft Defender allows an authorized attacker to elevate privileges locally.

State
PUBLISHED
Published
May 20, 2026
Updated
Jun 19, 2026
Evidence coverage
85%
CISA KEVCatalog member

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

FIRST EPSS8.37%

2026-07-18 · v2026.06.15 · percentile 94.3%

Source stateNo scored conflict

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

microsoftoriginal assertion
container

Microsoft Defender Elevation of Privilege Vulnerability

CISA KEVoriginal assertion
observed_exploitation

Microsoft Defender Link Following Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.083710000000; percentile 0.943420000000

Applicability

Cited product scope

Trace impact →
MicrosoftMicrosoft Malware Protection Engine
[{"status": "affected", "version": "1.1.0.0", "lessThan": "1.1.26040.8", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:microsoft:malware_protection_engine:*:*:*:*:*:*:*:*; start including 1.1.26030.3008; end excluding 1.1.26040.8supported

Assessments

CVSS by origin

7.8
secure@microsoft.comCVSS 3.1 · role SecondaryCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8
microsoftCVSS 3.1 · role unknownCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.