How severe is CVE-2023-42917?

CVE-2023-42917 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-2023-42917 being actively exploited?

Yes. CVE-2023-42917 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2023-12-04, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2023-42917?

CVE-2023-42917 primarily affects Apple Safari. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-42917?

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-2023-42917 have an EU (EUVD) identifier?

Yes. CVE-2023-42917 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-47338. It is also flagged as exploited in the EUVD (since 2023-12-04).

When was CVE-2023-42917 published?

CVE-2023-42917 was published on 2023-11-30 and last updated on 2026-06-17.

CVE-2023-42917

CVE-2023-42917 is a high-severity vulnerability in Apple Safari 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 2023-12-04). The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 9% (95th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2023-12-04)
EU (EUVD) id: EUVD-2023-47338
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2023-12-04)
Weakness: CWE-787
Affected product: Apple Safari
Published: 2023-11-30
Last modified: 2026-06-17

Description

A memory corruption vulnerability was addressed with improved locking. This issue is fixed in iOS 17.1.2 and iPadOS 17.1.2, macOS Sonoma 14.1.2, Safari 17.1.2. Processing web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been exploited against versions of iOS before iOS 16.7.1.

Frequently asked questions

What is CVE-2023-42917?: A memory corruption vulnerability was addressed with improved locking. This issue is fixed in iOS 17.1.2 and iPadOS 17.1.2, macOS Sonoma 14.1.2, Safari 17.1.2. Processing web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been exploited against versions of iOS before iOS 16.7.1.
How severe is CVE-2023-42917?: CVE-2023-42917 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-2023-42917 being actively exploited?: Yes. CVE-2023-42917 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2023-12-04, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2023-42917?: CVE-2023-42917 primarily affects Apple Safari. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-42917?: 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-2023-42917 have an EU (EUVD) identifier?: Yes. CVE-2023-42917 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-47338. It is also flagged as exploited in the EUVD (since 2023-12-04).
When was CVE-2023-42917 published?: CVE-2023-42917 was published on 2023-11-30 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:*
cpe:2.3:a:webkitgtk:webkitgtk\+:*:*:*:*:*:*:*:*

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