How severe is CVE-2026-43809?

CVE-2026-43809 has a CVSS 3.x base score of 9.8, 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 high, and availability high.

Is CVE-2026-43809 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-43809?

CVE-2026-43809 affects Apple Macos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-43809?

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-2026-43809 published?

CVE-2026-43809 was published on 2026-07-27 and last updated on 2026-08-17.

CVE-2026-43809

CVE-2026-43809 is a critical-severity vulnerability in Apple Macos with a CVSS 3.x base score of 9.8. 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 9.8)
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Apple Macos
Published: 2026-07-27
Last modified: 2026-08-17

Description

An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. An app may be able to cause unexpected system termination.

Frequently asked questions

What is CVE-2026-43809?: An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. An app may be able to cause unexpected system termination.
How severe is CVE-2026-43809?: CVE-2026-43809 has a CVSS 3.x base score of 9.8, 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 high, and availability high.
Is CVE-2026-43809 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43809?: CVE-2026-43809 affects Apple Macos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-43809?: 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-2026-43809 published?: CVE-2026-43809 was published on 2026-07-27 and last updated on 2026-08-17.

References

Affected products (1)

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

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