High-severity kernel use-after-free across multiple Apple OSes (iOS/macOS/tvOS/watchOS/visionOS) with CVSS 9.8; impacts large fleets and can destabilize or compromise endpoints.
CVE-2026-43778
Use-after-free in Apple kernels can crash devices or corrupt kernel memory.
Is CVE-2026-43778 being exploited?
Not confirmed. CVE-2026-43778 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.65% probability of exploitation in the next 30 days.
How severe is CVE-2026-43778?
CVE-2026-43778 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-43778?
Yes. A fix has been recorded for CVE-2026-43778. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-43778 affect?
CVE-2026-43778 affects iOS 26.6, iPadOS 26.6, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and 4 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-43778?
Deploy vendor updates to all Apple devices immediately
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
A malicious app can cause system termination (DoS) or corrupt kernel memory; may enable privilege escalation or kernel compromise.
Immediate action required
- affected< 18.7.10
- affected< 26.6
- affected< 14.8.8
- affected< 15.7.8
- affected< 26.6
- affected< 26.6
- affected< 26.6
- affected< 26.6
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.