CVE-2026-43666

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 18.7.9 and iPadOS 18.7.9, iOS 26.5 and iPadOS 26.5, macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, watchOS 26.5. An attacker on the local network may be able to cause a denial-of-service.

Published: 2026-05-11 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-43666 is rated Low Risk (27.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-43666

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-12 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-43666

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.2 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.5 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-43666

GitHub Security Advisory for CVE-2026-43666

GHSA-cm8r-x63q-3wvp · Severity: medium — An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in...

Affected software / configurations for CVE-2026-43666

Vendor Product Version Raw CPE
apple ipados < 18.7.9 cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
apple ipados >= 26.0, < 26.5 cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
apple iphone_os < 18.7.9 cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple iphone_os >= 26.0, < 26.5 cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple macos >= 14.0, < 14.8.7 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
apple macos >= 15.0, < 15.7.7 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
apple macos >= 26.0, < 26.5 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
apple tvos < 26.5 cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
apple visionos < 26.5 cpe:2.3:o:apple:visionos:*:*:*:*:*:*:*:*
apple watchos < 26.5 cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*

References for CVE-2026-43666

URL Tags
https://support.apple.com/en-us/127110 Release Notes Vendor Advisory
https://support.apple.com/en-us/127111 Release Notes Vendor Advisory
https://support.apple.com/en-us/127115 Release Notes Vendor Advisory
https://support.apple.com/en-us/127116 Release Notes Vendor Advisory
https://support.apple.com/en-us/127117 Release Notes Vendor Advisory
https://support.apple.com/en-us/127118 Release Notes Vendor Advisory
https://support.apple.com/en-us/127119 Release Notes Vendor Advisory
https://support.apple.com/en-us/127120 Release Notes Vendor Advisory
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