EUVD-2026-73801
GHSA-63ph-mjfv-6m29
Severity by source
AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Network-reachable kernel UAF requiring race-condition exploitation (AC:H); no credentials or user interaction needed; full C/I/A impact on successful kernel-level exploitation.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
5DescriptionCVE.org
Use after free in Reliable Multicast Transport Driver (RMCAST) allows an unauthorized attacker to execute code over a network.
AnalysisAI
Remote code execution via a use-after-free defect in the Windows Reliable Multicast Transport Driver (RMCAST) allows an unauthenticated network attacker to execute arbitrary code on affected Windows Server and Windows 10 systems. The vulnerability resides in a kernel-mode multicast transport driver, and successful exploitation achieves full confidentiality, integrity, and availability impact per CVSS C:H/I:H/A:H. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | The RMCAST/PGM Windows feature must be explicitly installed and active on the target system - this is an optional component not present in default Windows Server installations, requiring deliberate installation via Add Roles and Features or equivalent. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 8.1 score (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H) reflects a high-severity unauthenticated network-exploitable kernel UAF - a class historically capable of yielding SYSTEM-level code execution on Windows. … 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 security updates to bring affected builds to: Windows Server 2025 and Windows Server 2025 Server Core to 10.0.26100.33438 or later, Windows Server 2022 to 10.0.20348.5622 or later, and Windows Server 2019/Windows 10 Version 1809 to 10.0.17763.9245 or later. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, inventory all Windows Server and Windows 10 systems; disable RMCAST if multicast functionality is not operationally required. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
Same weakness CWE-416 – Use After Free
View allSame technique Use After Free
View allShare
External POC / Exploit Code
Leaving vuln.today