What is the CVSS score of CVE-2026-43655?

CVE-2026-43655 has a CVSS 3.1 base score of 7.3 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L. EPSS exploitation probability: 0.0%.

Which versions of Apple OS are affected by CVE-2026-43655?

CVE-2026-43655 is a high-severity out-of-bounds read vulnerability affecting Apple's iOS, iPadOS, macOS, tvOS, and watchOS version 26.5 that allows malicious applications to crash systems or extract…. A patch is available.

How to fix or mitigate CVE-2026-43655?

Within 24 hours: Inventory all Apple devices running iOS/iPadOS 26.5, macOS Tahoe 26.5, tvOS 26.5, and watchOS 26.5 in your environment. Within 7 days: Deploy vendor-released patches to all affected systems across these four operating system families. Within 30 days: Verify patch deployment completion and validate no systems remain on vulnerable versions through MDM or asset management tools.

Apple OS CVE-2026-43655

EUVD-2026-29301 HIGH

Out-of-bounds Read (CWE-125)

2026-05-11 apple

GHSA-6wgp-q874-jmmx

Apple Information Disclosure Buffer Overflow

7.3

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.3 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

Low

Lifecycle Timeline

Analysis Generated

May 12, 2026 - 18:24 vuln.today

CVSS changed

May 12, 2026 - 18:22 NVD

7.3 (HIGH)

Patch available

May 11, 2026 - 22:18 EUVD

CVE Published

May 11, 2026 - 20:08 nvd

UNKNOWN (no severity yet)

CVE Published

May 11, 2026 - 20:08 nvd

HIGH 7.3

DescriptionCVE.org

An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 26.5 and iPadOS 26.5, macOS Tahoe 26.5, tvOS 26.5, watchOS 26.5. An app may be able to cause unexpected system termination or read kernel memory.

AnalysisAI

Out-of-bounds read in Apple operating systems allows malicious applications to crash the system or leak kernel memory across iOS/iPadOS 26.5, macOS Tahoe 26.5, tvOS 26.5, and watchOS 26.5. The vulnerability requires local application execution but no user interaction, enabling information disclosure and denial-of-service attacks. Despite high CVSS 7.3 scoring, the EPSS probability is very low (0.02%, 5th percentile), indicating minimal observed exploitation activity. Vendor-released patches are available for all affected platforms.

Technical ContextAI

This vulnerability stems from CWE-125 (Out-of-bounds Read), a memory safety issue where insufficient bounds validation allows reading beyond allocated buffer boundaries. The flaw exists in a shared kernel-level component across Apple's operating system ecosystem (iOS, iPadOS, macOS, tvOS, watchOS), likely within a system call or inter-process communication mechanism accessible to third-party applications. Out-of-bounds reads can expose sensitive kernel memory contents including cryptographic keys, memory addresses for ASLR bypass, or other processes' data. The cross-platform nature indicated by CPE strings (cpe:2.3:a:apple:ios_and_ipados, cpe:2.3:a:apple:macos, cpe:2.3:a:apple:tvos, cpe:2.3:a:apple:watchos) suggests the vulnerable code exists in Apple's shared XNU kernel or a common framework layer. Apple addressed this through improved bounds checking, a standard mitigation that validates read operations stay within allocated memory regions.

RemediationAI

Update all Apple devices to version 26.5 or later through standard update mechanisms: iOS/iPadOS 26.5 (Settings > General > Software Update), macOS Tahoe 26.5 (System Settings > General > Software Update), tvOS 26.5 (Settings > System > Software Updates), watchOS 26.5 (Watch app > General > Software Update). Vendor advisories with detailed installation instructions are at https://support.apple.com/en-us/127110, https://support.apple.com/en-us/127115, https://support.apple.com/en-us/127118, and https://support.apple.com/en-us/127119. For environments unable to immediately patch, implement compensating controls by restricting application installation to Apple App Store sources only (disable developer mode, remove enterprise MDM profiles allowing sideloading, block jailbreak tools) to prevent malicious app execution, though this significantly limits device functionality for development and testing workflows. No kernel-level workarounds exist since the flaw requires code-level bounds checking fixes.