How severe is CVE-2016-4657?

CVE-2016-4657 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-4657 being actively exploited?

Yes. CVE-2016-4657 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2022-05-24, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2016-4657?

CVE-2016-4657 affects Apple Iphone Os. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-4657?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2016-4657 have an EU (EUVD) identifier?

Yes. CVE-2016-4657 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2016-5643. It is also flagged as exploited in the EUVD (since 2022-05-24).

When was CVE-2016-4657 published?

CVE-2016-4657 was published on 2016-08-25 and last updated on 2026-06-17.

CVE-2016-4657

CVE-2016-4657 is a high-severity vulnerability in Apple Iphone Os with a CVSS 3.x base score of 8.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2022-05-24). The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.8
EPSS exploit prediction: 67% (99th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2022-05-24)
EU (EUVD) id: EUVD-2016-5643
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2022-05-24)
Weakness: CWE-787
Affected product: Apple Iphone Os
Published: 2016-08-25
Last modified: 2026-06-17

Description

WebKit in Apple iOS before 9.3.5 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site.

Frequently asked questions

What is CVE-2016-4657?: WebKit in Apple iOS before 9.3.5 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site.
How severe is CVE-2016-4657?: CVE-2016-4657 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2016-4657 being actively exploited?: Yes. CVE-2016-4657 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2022-05-24, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2016-4657?: CVE-2016-4657 affects Apple Iphone Os. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-4657?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2016-4657 have an EU (EUVD) identifier?: Yes. CVE-2016-4657 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2016-5643. It is also flagged as exploited in the EUVD (since 2022-05-24).
When was CVE-2016-4657 published?: CVE-2016-4657 was published on 2016-08-25 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*

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