What is CVE-2026-50343?
Improper privilege management in Microsoft Install Service allows an authorized attacker to elevate privileges locally.
The record classifies CVE-2026-50343 under weakness class CWE-269. Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 11 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 118 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.8 — HIGH
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 - EPSS (FIRST)
- 0.2% probability of exploitation in the next 30 days, higher than 22.6% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 6.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-07-14
Is CVE-2026-50343 being exploited?
Weaponised exploit code for CVE-2026-50343 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 19 in the Threadlinqs vulnerability feed.
Affected products and versions
- Microsoft: 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)
How to fix CVE-2026-50343
The record marks a vendor fix as available for CVE-2026-50343. Patch reference: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50343. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2026-50343
No threat campaign in the Threadlinqs corpus currently references CVE-2026-50343, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories, public proof-of-concept repositories. This product uses the NVD API but is not endorsed or certified by the NVD.