EUVD-2026-73027
GHSA-r389-qw4c-wpm8
Severity by source
AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Local-only UAF requiring race condition (AC:H), low-privilege account entry point, no scope change; full CIA impact on successful SYSTEM escalation.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
4DescriptionCVE.org
Use after free in Microsoft Install Service allows an authorized attacker to elevate privileges locally.
AnalysisAI
Use-after-free in Windows Install Service permits local privilege escalation to SYSTEM on all actively supported Windows platforms. An authorized low-privilege local user can exploit a freed memory object in the service to corrupt heap structures and gain full control (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 | Requires an existing low-privilege local account (PR:L) with the ability to interact with the Windows Installer service - this is available to any standard authenticated user by default on Windows. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 vector AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H scores 7.0 - a Medium-High rating appropriate for a local privilege escalation with race-condition complexity. … 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-issued cumulative security update that delivers the fixed build numbers listed above, available through Windows Update, WSUS, or the Microsoft Update Catalog; the authoritative advisory is at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69605. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, inventory Windows systems using your endpoint management console and assess which environments have unauthorized local user access risk; simultaneously, prioritize systems for patching based on exposure (internet-facing) and importance (high-value workstations and servers). …
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