CVE-2023-42917: Apple Multiple Products WebKit Memory Corruption Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on , 4 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 9.3%
EPSS score, percentile 95.4 of all scored records
- How severe?
- 8.8 High
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA deadline . Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- before 17.1
- before 14.1
- before 17.1
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
What to do
Required action, set by CISA
Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
CISA due date for this action: .
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
- https://support.apple.com/en-us/HT214031
- https://support.apple.com/en-us/HT214032
- https://support.apple.com/en-us/HT214033
- https://nvd.nist.gov/vuln/detail/CVE-2023-42917
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | before 17.1 |
| Status | Versions |
|---|---|
| Affected | before 14.1 |
| Status | Versions |
|---|---|
| Affected | before 17.1 |
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
About this vulnerability
Apple iOS, iPadOS, macOS, and Safari WebKit contain a memory corruption vulnerability that leads to code execution when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.
Summary: CISA's KEV catalog, as of .
- CISA added CVE-2023-42917 to its Known Exploited Vulnerabilities (KEV) catalog on 4 Dec 2023.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 25 Dec 2023.
- The CVE record was published on 30 Nov 2023, 4 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 8.8 (High), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 9.3% (percentile 95.4), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
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.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
Weakness
- CWE-787: Out-of-bounds Write
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| Added to CISA KEV | |
| CISA due date for the required action | |
| CVE record last updated |
References
- support.apple.com
- support.apple.com
- support.apple.com
- support.apple.com
- openwall.com
- lists.fedoraproject.org
- lists.fedoraproject.org
- support.apple.com
- debian.org
- seclists.org
- seclists.org
- seclists.org
6 more in the CVE record.
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- CVE-2026-86950: Apple Multiple Products Out-of-Bounds Write Vulnerability
- CVE-2026-65400: Apple macOS Improper Authentication Vulnerability
- CVE-2025-31277: Apple Multiple Products Buffer Overflow Vulnerability
- CVE-2025-43510: Apple Multiple Products Improper Locking Vulnerability
- CVE-2025-43520: Apple Multiple Products Classic Buffer Overflow Vulnerability
- CVE-2021-30952: Apple Multiple Products Integer Overflow or Wraparound Vulnerability