CVE-2026-50343
HIGH 7.8 ALL-YEARSImproper privilege management in Microsoft Install Service allows an authorized attacker to elevate privileges locally.
Severe if exploited (CVSS 7.8), but no confirmed exploitation. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 22nd percentile
Impact if exploited
7.8CVSS 3.1 · HIGH · CNA
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
Search for new PoCs
Search GitHub now — results may be empty or unverified.
Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Affected
Vendors Microsoft
Products Windows 10 Version 1809 Windows 10 Version 21h2 Windows 10 Version 22h2 Windows 11 Version 24h2 Windows 11 Version 25h2 Windows 11 Version 26h1 Windows Server 2019 Windows Server 2019 (Server Core Installation) Windows Server 2022 Windows Server 2025 Windows Server 2025 (Server Core Installation) Windows 10 1809 Windows 10 21h2 Windows 10 22h2 Windows 11 24h2 Windows 11 25h2 Windows 11 26h1
Weakness (CWE)
- CWE-269: : Improper Privilege Management
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
References and research data (JSON)
Unverified PoC candidates
Catalogue matches for further research. These repositories have not been validated as working exploits.
1 candidate
- https://github.com/Rat5ak/CVE-2026-50343-InstallService-EoP
CVE-2026-50343 InstallService StaticPluginMap EoP - standard user to SYSTEM
PoC-in-GitHub · CVE-2026-50343
PoC-in-GitHub · CVE-2026-50343 · Updated 2026-09-23T13:52:17Z
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Microsoft | Windows 10 1809 | < 10.0.17763.9020 |
| Microsoft | Windows 10 1809 | < 10.0.17763.9020 |
| Microsoft | Windows 10 21h2 | < 10.0.19044.7548 |
| Microsoft | Windows 10 21h2 | < 10.0.19044.7548 |
| Microsoft | Windows 10 21h2 | < 10.0.19044.7548 |
| Microsoft | Windows 10 22h2 | < 10.0.19045.7548 |
| Microsoft | Windows 10 22h2 | < 10.0.19045.7548 |
| Microsoft | Windows 10 22h2 | < 10.0.19045.7548 |
| Microsoft | Windows 11 24h2 | < 10.0.26100.8875 |
| Microsoft | Windows 11 24h2 | < 10.0.26100.8875 |
| Microsoft | Windows 11 25h2 | < 10.0.26200.8875 |
| Microsoft | Windows 11 25h2 | < 10.0.26200.8875 |
| Microsoft | Windows 11 26h1 | < 10.0.28000.2269 |
| Microsoft | Windows 11 26h1 | < 10.0.28000.2525 |
| Microsoft | Windows Server 2019 | < 10.0.17763.9020 |
| Microsoft | Windows Server 2022 | < 10.0.20348.5386 |
| Microsoft | Windows Server 2025 | < 10.0.26100.33158 |
All CVSS metrics
- HIGH 7.8 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - HIGH 7.8 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
Patches & mitigations
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50343 CVE record · microsoft · Updated 2026-10-08T18:14:43.561Z
NVD · CVE-2026-50343 · Updated 2026-07-22T16:17:42.747
Advisories
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-43876 EUVD · EUVD-2026-43876
Sources: NVD · CVE.org · All sources and attribution · EPSS