How severe is CVE-2016-4609?

CVE-2016-4609 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-4609 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-4609?

CVE-2016-4609 primarily affects Apple Iphone Os. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-4609?

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

When was CVE-2016-4609 published?

CVE-2016-4609 was published on 2016-07-22 and last updated on 2026-06-17.

CVE-2016-4609

CVE-2016-4609 is a critical-severity vulnerability in Apple Iphone Os with a CVSS 3.x base score of 9.8. 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-119.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Apple Iphone Os
Published: 2016-07-22
Last modified: 2026-06-17

Description

libxslt in Apple iOS before 9.3.3, OS X before 10.11.6, iTunes before 12.4.2 on Windows, iCloud before 5.2.1 on Windows, tvOS before 9.2.2, and watchOS before 2.2.2 allows remote attackers to cause a denial of service (memory corruption) or possibly have unspecified other impact via unknown vectors, a different vulnerability than CVE-2016-4607, CVE-2016-4608, CVE-2016-4610, and CVE-2016-4612.

Frequently asked questions

What is CVE-2016-4609?: libxslt in Apple iOS before 9.3.3, OS X before 10.11.6, iTunes before 12.4.2 on Windows, iCloud before 5.2.1 on Windows, tvOS before 9.2.2, and watchOS before 2.2.2 allows remote attackers to cause a denial of service (memory corruption) or possibly have unspecified other impact via unknown vectors, a different vulnerability than CVE-2016-4607, CVE-2016-4608, CVE-2016-4610, and CVE-2016-4612.
How severe is CVE-2016-4609?: CVE-2016-4609 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2016-4609 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-4609?: CVE-2016-4609 primarily affects Apple Iphone Os. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-4609?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2016-4609 published?: CVE-2016-4609 was published on 2016-07-22 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:a:xmlsoft:libxslt:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
cpe:2.3:a:apple:icloud:*:*:*:*:*:*:*:*
cpe:2.3:a:apple:itunes:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*

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