EUVD-2026-56383
GHSA-f437-q7vg-jqrw
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Local access with low user privileges required; use-after-free in Schannel enables SYSTEM execution, justifying full C/I/A High with no scope change.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
3DescriptionCVE.org
Use after free in Windows Schannel allows an authorized attacker to elevate privileges locally.
AnalysisAI
Privilege escalation in Windows Schannel via a use-after-free (CWE-416) memory corruption flaw allows a locally authenticated, low-privileged attacker to elevate privileges - likely to SYSTEM - on Windows 11 and Windows Server 2025 systems. The CVSS 7.8 vector (AV:L/AC:L/PR:L/UI:N) reflects reliable, low-complexity exploitation requiring only a standard user account and no user interaction. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires an active low-privileged local user session on the target machine - the CVSS PR:L metric confirms a standard (non-administrator) account is sufficient. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 7.8 base score is well-supported by the vector: AV:L rules out remote unauthenticated exploitation but does not diminish the severity for post-compromise scenarios, where local privilege escalation is a critical step in ransomware deployment and lateral movement. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | Apply the Microsoft-released patch via Windows Update, WSUS, or Microsoft Update Catalog targeting the following minimum fixed builds: Windows 11 26H1 to 10.0.28000.2704 or later; Windows 11 24H2 and Windows Server 2025 (including Server Core) to 10.0.26100.33296 or later; Windows 11 25H2 to 10.0.26200.9168 or later. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify and inventory all Windows 11 and Windows Server 2025 systems and segment by criticality (those handling sensitive data or administrative functions first). …
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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
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