CVE-2026-33825: Microsoft Defender Insufficient Granularity of Access Control Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 22 Apr 2026, 8 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 6.7%
EPSS score, percentile 93.9 of all scored records
- How severe?
- 7.8 High
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA deadline 6 May 2026. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Which versions are affected?
Affected
- from 4.0.0.0 to before 4.18.26030.3011
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
What to do
Required action, set by CISA
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA due date for this action: 6 May 2026.
Advisories and patches
Linked from CISA's catalog entry
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33825
- https://nvd.nist.gov/vuln/detail/CVE-2026-33825
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from 4.0.0.0 to before 4.18.26030.3011 |
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
Microsoft Defender contains an insufficient granularity of access control vulnerability that could allow an authorized attacker to escalate privileges locally.
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2026-33825 to its Known Exploited Vulnerabilities (KEV) catalog on 22 Apr 2026.
- CISA marks it as known to be used in ransomware campaigns.
- The due date CISA sets for the required action is 6 May 2026.
- The CVE record was published on 14 Apr 2026, 8 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 7.8 (High), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 6.7% (percentile 93.9), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
Description
Microsoft Defender Elevation of Privilege Vulnerability
Insufficient granularity of access control in Microsoft Defender allows an authorized attacker to elevate privileges locally.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
Weakness
- CWE-1220: Insufficient Granularity of Access Control
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| 14 Apr 2026 | CVE record published |
| 22 Apr 2026 | Added to CISA KEV |
| 6 May 2026 | CISA due date for the required action |
| 15 Oct 2026 | CVE record last updated |
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