What is the CVSS score of CVE-2026-43799?

CVE-2026-43799 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.2%.

Which versions of Apple iOS are affected by CVE-2026-43799?

A critical denial-of-service vulnerability affects Apple's entire ecosystem (iOS, iPadOS, macOS, tvOS, visionOS, watchOS), allowing locally-installed malicious applications to crash devices and…. A patch is available.

How to fix or mitigate CVE-2026-43799?

Within 24 hours, inventory all Apple devices across iOS, macOS, tvOS, visionOS, and watchOS to assess deployment scale and identify critical systems. Within 7 days, deploy available vendor patches to all company-managed macOS systems and corporate-issued iOS/iPadOS devices via MDM or corporate distribution channels, and communicate patch availability to BYOD users with guidance on manual update. Complete patch deployment across all remaining devices by day 30, validate coverage through mobile device management dashboards, and maintain an updated device inventory for future vulnerability response.

Apple iOS CVE-2026-43799

EUVD-2026-49447 CRITICAL

Use After Free (CWE-416)

2026-07-27 apple

GHSA-347f-3cff-8gh8

Denial Of Service Use After Free Memory Corruption Apple Tvos Visionos Watchos Ios And Ipados

9.8

CVSS 3.1 · Vendor: apple

Severity by source

Vendor (apple) PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

vuln.today AI

5.5 MEDIUM

Requires a locally installed/run app (AV:L, UI:R to install/launch); impact is only unexpected termination, so C:N/I:N/A:H, contradicting the NVD network C/I/A:H rating.

3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

4.0 AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (apple).

CVSS VectorVendor: apple

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Jul 28, 2026 - 16:24 vuln.today

CVSS changed

Jul 28, 2026 - 16:22 NVD

9.8 (CRITICAL)

Patch available

Jul 27, 2026 - 21:17 EUVD

CVE Published

Jul 27, 2026 - 20:14 cve.org

UNKNOWN (no severity yet)

CVE Published

Jul 27, 2026 - 20:14 cve.org

CRITICAL 9.8

DescriptionCVE.org

A use after free issue was addressed with improved memory management. This issue is fixed in iOS 26.6 and iPadOS 26.6, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6, tvOS 26.6, visionOS 26.6, watchOS 26.6. An app may be able to cause unexpected system termination.

AnalysisAI

Denial-of-service (unexpected system termination) affects Apple's shared OS platforms - iOS/iPadOS before 26.6, macOS Sequoia before 15.7.8, macOS Sonoma before 14.8.8, macOS Tahoe/tvOS/visionOS/watchOS before 26.6 - where a use-after-free (CWE-416) lets a locally installed app crash the system. There is no public exploit identified at time of analysis and the NVD CVSS 9.8 (C:H/I:H/A:H) conflicts with Apple's own description, which states only 'unexpected system termination' (availability impact), suggesting the true impact is a DoS crash rather than full compromise. EPSS is low (0.17%, 6th percentile) and the issue is not in CISA KEV.

Technical ContextAI

The root cause is a use-after-free (CWE-416): code continues to reference a memory region after it has been freed, allowing a dangling pointer to be dereferenced and corrupt process/kernel state, which Apple resolved 'with improved memory management.' Per the CPE data the flaw spans Apple's shared codebase across cpe:2.3:a:apple:ios_and_ipados, :macos, :tvos, :visionos and :watchos, indicating the vulnerable component is common framework/OS code reused across all Apple operating systems rather than a single product. The manifestation - an installed app triggering the condition - points to an app-reachable system service or kernel/framework interface whose object lifecycle is mishandled.

RemediationAI

Apply the vendor-released patches: upgrade to iOS/iPadOS 26.6, macOS Tahoe 26.6, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, tvOS 26.6, visionOS 26.6, and watchOS 26.6, which contain the improved memory-management fix. Consult the matching Apple security notes at https://support.apple.com/en-us/128066 through /128072 to map each note to your platform. Because exploitation requires a locally installed app, the primary compensating control until patching is restricting app installation to trusted/vetted sources (App Store / MDM-approved apps) and removing untrusted apps; on managed fleets, enforce MDM allow-listing - the trade-off is reduced user flexibility in installing arbitrary software.