How severe is CVE-2019-15315?

CVE-2019-15315 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2019-15315 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-15315?

CVE-2019-15315 affects Valvesoftware Steam Client. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-15315?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-15315 published?

CVE-2019-15315 was published on 2019-08-21 and last updated on 2026-06-17.

CVE-2019-15315

CVE-2019-15315 is a high-severity vulnerability in Valvesoftware Steam Client with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-732.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 7.2
EPSS exploit prediction: 0% (31st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-732
Affected product: Valvesoftware Steam Client
Published: 2019-08-21
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2019-15315?: 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.
How severe is CVE-2019-15315?: CVE-2019-15315 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-15315 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-15315?: CVE-2019-15315 affects Valvesoftware Steam Client. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-15315?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-15315 published?: CVE-2019-15315 was published on 2019-08-21 and last updated on 2026-06-17.

References

https://xiaoyinl.github.io/steam_EoP_bypass.html

Affected products (1)

cpe:2.3:a:valvesoftware:steam_client:*:*:*:*:*:*:*:*

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