Improper input validation in Microsoft Windows Server 2012 R2
CVE-2026-33826
Improper input validation in Windows Active Directory allows an authorized attacker to execute code over an adjacent network.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.009 (76.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.0 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C.
Affected products
- Microsoft Windows Server 2012 R2 — versions 6.3.9600.0
- Microsoft Windows Server 2012 R2 (Server Core Installation) — versions 6.3.9600.0
- Microsoft Windows Server 2016 — versions 10.0.14393.0
- Microsoft Windows Server 2016 (Server Core Installation) — versions 10.0.14393.0
- Microsoft Windows Server 2019 — versions 10.0.17763.0
- Microsoft Windows Server 2019 (Server Core Installation) — versions 10.0.17763.0
- Microsoft Windows Server 2022 — versions 10.0.20348.0
- Microsoft Windows Server 2022, 23h2 Edition (Server Core Installation) — versions 10.0.25398.0
- Microsoft Windows Server 2025 — versions 10.0.26100.0
- Microsoft Windows Server 2025 (Server Core Installation) — versions 10.0.26100.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- Windows Active Directory Remote Code Execution Vulnerability (vendor-advisory, patch)
Frequently asked questions
- What is CVE-2026-33826?
- CVE-2026-33826 is a high-severity vulnerability in Microsoft Windows Server 2012 R2, classified under Improper Input Validation. CVSS score: 8.0/10. Published 2026-04-14.
- How severe is CVE-2026-33826?
- High severity. CVSS v3 base score is 8.0 out of 10.
- Is CVE-2026-33826 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.