An issue was discovered in Valve Steam Client 2.10.91.91.
Priority LOW 35CWE-362Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
An issue was discovered in Valve Steam Client 2.10.91.91. The installer allows local users to gain NT AUTHORITY\SYSTEM privileges because some parts of %PROGRAMFILES(X86)%\Steam and/or %COMMONPROGRAMFILES(X86)%\Steam have weak permissions during a critical time window. An attacker can make this time window arbitrarily long by using opportunistic locks.
Why it matters now
EPSS 0.00545 45th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:valvesoftware:steam_client:2.10.91.91:*:*:*:*:*:*:* | 2.10.91.91 | Vulnerable | Valvesoftware |
- cpe:2.3:a:valvesoftware:steam_client:2.10.91.91:*:*:*:*:*:*:* Versions 2.10.91.91 Vulnerable ·Valvesoftware
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2020-15530
- 2026-10-03 Alias added: GHSA-x228-hc8r-8rjq
References
More Valvesoftware Steam Client vulnerabilities
- TI-2021-10883 Valve Steam before 2021-04-17, when a Source engine game is installed, allows remote… CVSS 3.1CRITICAL 9.0
- TI-2019-12806 Valve Steam Client before 2019-09-12 allows placing or appending partially controlled… CVSS 3.1HIGH 7.8
- TI-2019-11419 Valve Steam Client for Windows through 2019-08-16 allows privilege escalation (to NT… CVSS 3.0HIGH 7.8
- TI-2015-06635 Valve Steam 2.10.91.91 uses weak permissions (Users: read and write) for the Install… CVSS 2.0HIGH 7.2
- TI-2019-11420 Valve Steam Client for Windows through 2019-08-20 has weak folder permissions, leading to… CVSS 3.0HIGH 7.0
- TI-2019-10955 In Valve Steam Client for Windows through 2019-08-07… CVSS 3.0MEDIUM 6.6
Sources
- CVE-2020-15530 · CVE Program
- CVE-2020-15530 · NVD
- FIRST EPSS
- GHSA-x228-hc8r-8rjq · GitHub Advisory Database · CC BY 4.0
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