Windows Server 2025
CVE-2026-20854
HIGH
Severity by source
AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Primary rating from Vendor (microsoft) · only source for this CVE.
CVSS VectorVendor: microsoft
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
2DescriptionCVE.org
Use after free in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to execute code over a network.
AnalysisAI
Remote code execution in Windows LSASS (Local Security Authority Subsystem Service) on Windows 11 and Windows Server 2025 stems from a use-after-free memory vulnerability exploitable by authenticated attackers over the network. An attacker with valid credentials can trigger the flaw to execute arbitrary code with SYSTEM privileges, achieving complete system compromise. No patch is currently available, leaving affected systems vulnerable until Microsoft releases a security update.
Technical ContextAI
Classified as CWE-416 (Use After Free). Affects Windows 11 24H2. Use after free in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to execute code over a network.
RemediationAI
Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.
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Same weakness CWE-416 – Use After Free
View allSame technique Use After Free
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External POC / Exploit Code
Leaving vuln.today