EUVD-2026-73004
GHSA-9rch-hmj9-5v86
Severity by source
AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Local-only vector, low-priv authenticated attacker, high complexity for heap exploitation; full system compromise upon success justifies C:H/I:H/A:H.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
3DescriptionCVE.org
Heap-based buffer overflow in Windows Fax Service allows an authorized attacker to elevate privileges locally.
AnalysisAI
Heap-based buffer overflow in Windows Fax Service enables a low-privileged local attacker to escalate privileges to SYSTEM on a wide range of Windows client and server versions. The flaw (CWE-122) is confirmed patched by Microsoft via their monthly update cycle, with fixed build numbers available across every affected version from Windows Server 2012 through Windows 11 26H1. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires: (1) an existing authenticated session on the target system with at minimum a standard (low-privileged) user account - confirmed by CVSS PR:L; (2) Windows Fax Service (fax/fxssvc.exe) must be running on the target - this service is not enabled by default on all Windows configurations and must be actively started or configured to start automatically; (3) high attack complexity (CVSS AC:H) indicates additional exploitation prerequisites such as a specific heap state or timing condition must be met, making reliable exploitation non-trivial. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | Real-world risk is moderate despite the all-high C/I/A impact scores. … 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 security update issued for this CVE through Windows Update, WSUS, Microsoft Update Catalog, or equivalent patch management tooling. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify all Windows systems running Fax Service-particularly Windows Server deployments (2012 R2 SP1, 2016, 2019, 2022) and Windows 10/11 workstations. …
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Same weakness CWE-122 – Heap-based Buffer Overflow
View allSame technique Buffer Overflow
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External POC / Exploit Code
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