EUVD-2026-73226
GHSA-gpxw-2w54-r4m7
Severity by source
AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Local vector for FAT volume mount; no credentials needed; AC:H for crafted filesystem structure; full kernel-level C/I/A impact.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
3DescriptionCVE.org
Heap-based buffer overflow in Windows Fast FAT Driver allows an unauthorized attacker to execute code locally.
AnalysisAI
Heap-based buffer overflow in the Windows Fast FAT filesystem driver (fastfat.sys) enables local code execution across a wide range of Windows client and server versions. The vulnerability is reachable without elevated privileges (PR:N, AV:L) under high-complexity conditions, suggesting a crafted FAT volume - such as a malicious USB drive or mounted disk image - can trigger the overflow in kernel space. …
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 | Exploitation requires that the attacker can cause Windows to mount or parse a crafted FAT filesystem - the most direct path is physical access to insert removable media (USB drive, SD card) that Windows auto-mounts, but a non-privileged local user who can mount a VHD or ISO image containing a FAT volume achieves the same effect. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The provided CVSS 7.4 (AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H) reflects a kernel-level local privilege escalation with full-system impact potential, but bounded by high attack complexity and the local attack vector. … 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 update via Windows Update or WSUS immediately. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, inventory which Windows client and server systems have removable media enabled or mount external storage, and prioritize systems in production or user-accessible environments. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
Same weakness CWE-122 – Heap-based Buffer Overflow
View allSame technique Buffer Overflow
View allShare
External POC / Exploit Code
Leaving vuln.today