How severe is CVE-2016-4639?

CVE-2016-4639 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-2016-4639 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-4639?

CVE-2016-4639 affects Apple Mac Os X. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-4639?

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-2016-4639 published?

CVE-2016-4639 was published on 2016-07-22 and last updated on 2026-06-17.

CVE-2016-4639

CVE-2016-4639 is a high-severity vulnerability in Apple Mac Os X 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.

Key facts

Severity: High (CVSS 3.x base score 7.0)
CVSS v2: 4.4
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Apple Mac Os X
Published: 2016-07-22
Last modified: 2026-06-17

Description

Login Window in Apple OS X before 10.11.6 does not properly initialize memory, which allows local users to cause a denial of service via unspecified vectors.

Frequently asked questions

What is CVE-2016-4639?: Login Window in Apple OS X before 10.11.6 does not properly initialize memory, which allows local users to cause a denial of service via unspecified vectors.
How severe is CVE-2016-4639?: CVE-2016-4639 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-2016-4639 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-4639?: CVE-2016-4639 affects Apple Mac Os X. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-4639?: 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-2016-4639 published?: CVE-2016-4639 was published on 2016-07-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*

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