CVE-2026-33825 KEVRansomwarePublic exploit High · 7.8 EPSS 6.7%
Microsoft Defender Insufficient Granularity of Access Control Vulnerability
Microsoft · Defender
Summary
The flaw is an insufficient granularity of access control in Microsoft Defender, a Microsoft product. An attacker who already holds authorized access on the local system can use it to elevate their privileges.
Official description · NVD
Insufficient granularity of access control in Microsoft Defender allows an authorized attacker to elevate privileges locally.
Priority scorePatchfirst’s 0 to 100 ranking. It adds points for CISA KEV listing, ransomware use, EPSS, threat reports, public exploit code and CVSS. Every CVE page shows the breakdown. Breakdown
82.3 / 100
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 4/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.How attackers get in
What they do
Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 2 days after disclosure. Public exploit code (PoC-in-GitHub) appeared 3 days after disclosure.
- Disclosedday 0
- First seen exploitedVulnCheck KEV evidence+2 days
- Public exploit codePoC-in-GitHub+3 days
- Added to CISA KEVknown ransomware use; EU database agrees+8 days
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
2 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order, 2 cited passages 2Initial AccessTA0001
Valid Accounts T1078 Medium Confidence (technique links)How sure Patchfirst is that an ATT&CK technique applies to this CVE. High and medium links are shown by default; low ones come from early or generic mappings, text matching, or contradict the CVE’s details. also Persistence, Privilege Escalation, Stealth
AI mapping from the description · how it is exploited
Requires an authorized local account already present
allows an authorized attacker to elevate privileges locally
Privilege EscalationTA0004
Exploitation for Privilege Escalation T1068 Medium Confidence (technique links)How sure Patchfirst is that an ATT&CK technique applies to this CVE. High and medium links are shown by default; low ones come from early or generic mappings, text matching, or contradict the CVE’s details.
AI mapping from the description · primary impact
Insufficient access control enables local privilege escalation
allows an authorized attacker to elevate privileges locally
Detection
0 rules for this CVE · 87 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2026-33825 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Valid AccountsT107856 general rules
- Win Susp Computer Name Containing Samtheadmincriticaltest
- Account Created And Deleted Within A Close Time Framehightest
- Activity From Anonymous IP Addresshightest
- Atypical Travelhightest
- Azure AD Threat Intelligencehightest
- Azure Subscription Permission Elevation Via AuditLogshightest
- External Remote SMB Logon from Public IPhightest
- Impossible Travelhightest
Exploitation for Privilege EscalationT106831 general rules
- Exploiting CVE-2019-1388criticalstable
- Audit CVE Eventcriticaltest
- HackTool - SysmonEOP Executioncriticaltest
- InstallerFileTakeOver LPE CVE-2021-41379 File Create Eventcriticaltest
- Possible Coin Miner CPU Priority Paramcriticaltest
- Potential CVE-2021-41379 Exploitation Attemptcriticaltest
- Potential SystemNightmare Exploitation Attemptcriticaltest
- Sudo Privilege Escalation CVE-2019-14287 - Builtincriticaltest
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Not named in any threat report yetAlso mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 31, 202630 Oct 2026
- Actively_Exploited_Kev | Oct 30, 202629 Oct 2026
- The Science of Exploitability: Decoding BlueHammer28 Oct 2026
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- 44 more on OTX