CVE-2019-15315: Valvesoftware Steam Client

High severity, CVSS 7.8. EPSS: 0.4% chance of exploitation in the next 30 days.

Valve Steam Client for Windows through 2019-08-16 allows privilege escalation (to NT AUTHORITY\SYSTEM) because local users can replace the current versions of SteamService.exe and SteamService.dll with older versions that lack the CVE-2019-14743 patch.

Affected products

• Valvesoftware Steam Client: up to and including 2019-08-16

Published 2019-08-21. Last modified 2026-06-17.