How severe is CVE-2019-15316?

CVE-2019-15316 has a CVSS 3.x base score of 7.0, rated high severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2019-15316 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-2019-15316?

CVE-2019-15316 affects Valvesoftware Steam Client. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-15316?

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-2019-15316 published?

CVE-2019-15316 was published on 2019-08-21 and last updated on 2026-06-17.

CVE-2019-15316

CVE-2019-15316 is a high-severity vulnerability in Valvesoftware Steam Client with a CVSS 3.x base score of 7.0. 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-367.

Key facts

Severity: High (CVSS 3.x base score 7.0)
CVSS v2: 6.9
EPSS exploit prediction: 0% (31st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-367
Affected product: Valvesoftware Steam Client
Published: 2019-08-21
Last modified: 2026-06-17

Description

Valve Steam Client for Windows through 2019-08-20 has weak folder permissions, leading to privilege escalation (to NT AUTHORITY\SYSTEM) via crafted use of CreateMountPoint.exe and SetOpLock.exe to leverage a TOCTOU race condition.

Frequently asked questions

What is CVE-2019-15316?: Valve Steam Client for Windows through 2019-08-20 has weak folder permissions, leading to privilege escalation (to NT AUTHORITY\SYSTEM) via crafted use of CreateMountPoint.exe and SetOpLock.exe to leverage a TOCTOU race condition.
How severe is CVE-2019-15316?: CVE-2019-15316 has a CVSS 3.x base score of 7.0, rated high severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-15316 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-2019-15316?: CVE-2019-15316 affects Valvesoftware Steam Client. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-15316?: 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-2019-15316 published?: CVE-2019-15316 was published on 2019-08-21 and last updated on 2026-06-17.

References

Affected products (1)

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

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