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Apexward Pulse
Type Vulnerability

Microsoft

Microsoft Defender Insufficient Granularity of Access Control Vulnerability

1 sourceCVE-2026-33825

At a glance

High
Suggested 24-hour window, counted from the last update
ActiveConfirmed in-the-wild exploitation
Evidence-weighted, not popularity
Signal

Actively exploited in the wild — prioritise confirming exposure.

Why High

High rather than Critical: exposure is scored at a default because we cannot see your systems or suppliers. If you run or depend on Microsoft Windows Server, treat it as Critical.

Briefing

  • Do not treat uncorroborated claims as confirmed breaches.

Questions to ask IT

  • Do we run Microsoft Windows Server, and which versions?
  • Is any of it reachable from the internet?
  • Have we checked whether it has already been used against us?
  • If it is still not patched, what mitigation is in place, and what is holding the fix up?

Next steps

  1. Confirm exposure, mitigation status and any service interruption risk.

Summary

  • Microsoft Defender contains an insufficient granularity of access control vulnerability that could allow an authorised attacker to escalate privileges locally.
  • CVE-2026-33825 is listed in known-exploited catalogue (exploitation in the wild)
  • Authoritative catalogues report active exploitation of this vulnerability.

Why this matters in the UK

  • Known-exploited catalogue reports exploitation in the wild

Products and services involved

Pulse

Last checked 4d ago · Recheck overdue since 5 Nov 2026, 21:06 UK time · 1 quiet check collapsed

Signal
9 Sept 2026, 06:45 UK time · 9 Sept

in the next 30 days first recorded at 6.7% (lower likelihood signal, not confirmed exploitation).

recorded — watch for changes; not confirmed exploitation.

EscalationDe-escalationCritical / liveWhat these mean
Drag to pan · Ctrl / ⌘ + scroll or pinch to zoom7 events

3 quiet checks hidden.

Sources

How we know

Statements extracted from sources. Higher confidence means stronger corroboration.

  • ConfirmedHeadline90% confidence

    Microsoft Defender Insufficient Granularity of Access Control Vulnerability

  • ConfirmedSummary fact75% confidence

    Microsoft Defender contains an insufficient granularity of access control vulnerability that could allow an authorised attacker to escalate privileges locally. Affects Microsoft Defender. Known ransomware campaign use: Known. Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

  • ConfirmedCVE identifier95% confidence

    Event involves CVE-2026-33825

  • ConfirmedKnown-exploited catalogue98% confidence

    CVE-2026-33825 is listed in known-exploited catalogue (exploitation in the wild)