CVE-2023-43000: Apple WebKit use-after-free memory corruption

Quick Answer

CISA added CVE-2023-43000 to its Known Exploited Vulnerabilities catalog on 2026-03-05, confirming that exploitation has occurred. If you operate Apple Multiple Products, identify the exact version and relevant configuration now, preserve security evidence, and follow the live vendor remediation. A KEV match does not prove your system was compromised, and installing an update does not rule out earlier exploitation.

Last verified: 2026-09-17 UTC. CISA KEV snapshot version 2026.09.16. Recheck the live advisory before changing production.

Context

Status At A Glance

Product scope	Apple — Multiple Products
CVE	CVE-2023-43000
TechGeeks response tier	P0 — confirm an exact match and act now
CISA KEV added	2026-03-05
Vendor severity	Not assigned or published by the vendor in the cited advisory.
CVSS	Not assigned or published by the vendor in the cited advisory.
Ransomware field	Unknown — this is not the same as No; CISA has not marked the field Known.
Forensic-triage field	No in the current CISA field; organizations should still investigate when exposure or evidence warrants it.
CWE	CWE-416
Federal remediation date	2026-03-26 — applies to covered federal agencies; other organizations should set a risk-based deadline.

What Happened

Apple Multiple products Use-After-Free Vulnerability. Apple macOS, iOS, iPadOS, and Safari 16.6 contain a use-after-free vulnerability due to the processing of maliciously crafted web content that may lead to memory corruption. CISA's KEV listing confirms exploitation evidence, but it does not state how widespread the activity is or prove that any particular installation was compromised.

Affected Scope

WebKit in Safari 16.6, iOS and iPadOS 16.6, and macOS Ventura 13.5; Apple later backported the fix to legacy devices in iOS and iPadOS 15.8.7.

Match the exact edition, hardware or virtual platform, release, patch level, enabled feature, and management exposure. A product-family name alone is not enough to establish applicability.

Steps

What To Do Now

1. Confirm. Inventory every Multiple Products asset and record its exact version, patch level, role, relevant configuration, and exposure.
2. Preserve. Save UTC timestamps, off-device authentication, firewall, proxy, DNS, endpoint, application, and SIEM evidence before logs rotate or a disruptive change removes context.
3. Contain. Restrict unnecessary internet and management-plane access using supported controls. Follow the live advisory: Open the live Apple advisory.
4. Remediate. Install the newest supported Apple operating-system and Safari update. Legacy devices that cannot move to a newer major release must run at least iOS or iPadOS 15.8.7.
5. Validate. Verify the resulting version or patch level, service health, logging, expected access, an expected denial, and representative dependent workflows.
6. Escalate. If exposure overlapped the vulnerable period or evidence is suspicious, treat the system as a potential incident and follow vendor and incident-response recovery guidance.

Fixed Releases And Mitigation

Verified fixed release, patch level, or update guidance captured at the last check:

• Safari 16.6
• iOS 16.6 and iPadOS 16.6
• macOS Ventura 13.5
• iOS 15.8.7 and iPadOS 15.8.7 legacy backport

Mitigation boundary: Apple documents software updates as the remedy and does not state a product-specific workaround in the cited advisories.

A workaround, access restriction, or provider-side control reduces a described path; it does not necessarily remove vulnerable code or erase compromise.

Investigation And Recovery

CISA added this CVE to KEV in 2026. Apple's March 2026 legacy advisory associates the backported fix with the Coruna exploit; old devices unable to move to a current major release deserve explicit inventory checks.

When an attacker may have gained administrative, root, SYSTEM, identity, management-plane, or code-execution access, patching alone is not an eradication claim. Preserve evidence, scope affected accounts and downstream systems, rotate exposed credentials or certificates when justified, and rebuild from a trusted source when vendor or incident-response guidance requires it.

Notes

Exploitation Evidence

Vendor statement: Apple's iOS and iPadOS 15.8.7 advisory says this fix is associated with the Coruna exploit.

CISA statement: CVE-2023-43000 was added to KEV on 2026-03-05. The ransomware field is Unknown, and the forensic-triage field is No. These are separate signals.

Validation And Boundaries

This notice does not prove that every product carrying the family name is affected, that exploitation is widespread, that a clean indicator search rules out compromise, or that a successful update restored trust. TechGeeks has not reproduced the exploit and does not replace the vendor advisory, asset inventory, vulnerability scanner, or incident-response process.

Related TechGeeks Resources

• Security Hot Page
• All Security Notices
• What to Do When a Device Hits CISA KEV
• Router CVE Exposure, Version, and Mitigation Checklist
• IoT Firmware Update and End-of-Support Checklist
• Live Protect and Runtime Vulnerability Shielding

References

• Apple security advisory
• Apple security advisory
• Apple security advisory
• Apple security advisory
• NVD CVE record
• CISA source

Wrap-Up

Record whether CVE-2023-43000 applies to your environment. If it does, assign an owner, preserve the change and investigation evidence, complete the vendor action, and document the validated result.

Correction policy: If a primary source changes affected versions, remediation, exploitation status, or recovery guidance, TechGeeks will update this page and its verification date.