Exploited CVEs / Apple / CVE-2023-42917

CVE-2023-42917

Apple Multiple Products WebKit Memory Corruption Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2023-12-25 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Apple security releases, linked below.

Risk summary

HighCISA KEV

8.8

CVSS base

9.4%

EPSS exploit probability

High

Severity

2023-12-04

Added to KEV

2023-12-25 (past due)

CISA due date

Actively exploited Apple Multiple Products vulnerability, High severity, CVSS 8.8. Added to the CISA KEV catalog 2023-12-04.

Senserva AI read on CVE-2023-42917 CISA required action Official fix for CVE-2023-42917 Admin questions

Senserva AI Opinion for CVE-2023-42917

Apple shipped an emergency fix for this WebKit memory corruption after it was exploited against real targets: maliciously crafted web content yields code execution on iOS, iPadOS, macOS, and Safari. It was deployed in tandem with an information-leak sibling, the classic two-bug pattern of a full browser exploit chain. Severity is High at CVSS 8.8, and the KEV listing dates to December 2023.

Do this: Update all Apple devices through MDM and confirm Safari on older macOS versions received its separate patch.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2023-42917

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I run IT security. Facts for CVE-2023-42917, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2023-42917.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2023-42917: Apple Multiple Products WebKit Memory Corruption Vulnerability
- Affected: Apple Multiple Products
- Severity: High, CVSS 8.8; EPSS 30-day exploitation probability 9.4%
- Added to CISA KEV: 2023-12-04; federal remediation due 2023-12-25
- Ransomware-linked: no
- CISA required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) The fastest safe path to remediation. 4) How to check whether my environment is exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch now

Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.

The fix ships from the vendor: Apple security releases.

Do this now: Federal remediation deadline 2023-12-25; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated August 14, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2023-42917

Published: 2023-12-04
Last revised: 2023-12-04
Changes tracked: 1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

Senserva Watchevery change we have recorded for this one

What changed, and when

2023-12-04 added to the CISA KEV catalog by CISA
2026-07-17 CVSS 0.0 to 8.8; EPSS first scored at 9.4%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

CISA required action

Federal (BOD 22-01) remediation due date: 2023-12-25 (past due).

Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Official fix for CVE-2023-42917

The authoritative fix and affected-version list are published by the vendor. Find the Multiple Products advisory on Apple security releases.

Apple security releases CISA KEV entry

Common questions about CVE-2023-42917

Is CVE-2023-42917 actively exploited?

Yes. CVE-2023-42917 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2023-12-04, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 9.4%.

What is the CISA deadline and required action for CVE-2023-42917?

CISA set the federal (BOD 22-01) remediation due date at 2023-12-25, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

What fixes CVE-2023-42917?

The authoritative fix is in the vendor advisory: see Apple security releases for the patched Multiple Products versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2023-42917?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2023-42917's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

Scope and sources

More exploited Apple CVEs: CVE-2025-31277 CVE-2025-43520 CVE-2025-43510 CVE-2021-30952 CVE-2023-43000 CVE-2023-41974 CVE-2026-20700 CVE-2025-43529
All Apple exploited CVEs on one page: Apple vulnerabilities actively exploited.
Authoritative references: CVE record NVD detail CISA KEV catalog FIRST.org EPSS

Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.