How severe is CVE-2023-40436?

CVE-2023-40436 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2023-40436 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-40436?

CVE-2023-40436 affects Apple Macos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-40436?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2023-40436 published?

CVE-2023-40436 was published on 2023-09-27 and last updated on 2026-06-17.

CVE-2023-40436

CVE-2023-40436 is a critical-severity vulnerability in Apple Macos with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 1% (59th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Apple Macos
Published: 2023-09-27
Last modified: 2026-06-17

Description

The issue was addressed with improved bounds checks. This issue is fixed in macOS Sonoma 14. An attacker may be able to cause unexpected system termination or read kernel memory.

Frequently asked questions

What is CVE-2023-40436?: The issue was addressed with improved bounds checks. This issue is fixed in macOS Sonoma 14. An attacker may be able to cause unexpected system termination or read kernel memory.
How severe is CVE-2023-40436?: CVE-2023-40436 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2023-40436 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-40436?: CVE-2023-40436 affects Apple Macos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-40436?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-40436 published?: CVE-2023-40436 was published on 2023-09-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*

More vulnerabilities in Apple Macos

CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2025-24085 — Critical (CVSS 10.0): A use after free issue was addressed with improved memory management. This issue is fixed in iOS 18.3 and iPadOS 18.3,…
CVE-2024-44148 — Critical (CVSS 10.0): This issue was addressed with improved validation of file attributes. This issue is fixed in macOS Sequoia 15. An app…
CVE-2024-44146 — Critical (CVSS 10.0): A logic issue was addressed with improved file handling. This issue is fixed in macOS Sequoia 15. An app may be able to…
CVE-2023-40455 — Critical (CVSS 10.0): A permissions issue was addressed with additional restrictions. This issue is fixed in macOS Sonoma 14. A sandboxed…

All CVEs affecting Apple Macos →

Other CWE-125 (Out-of-bounds Read) vulnerabilities

CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →