CVE-2023-40440

CVE-2023-40440 is a high-severity vulnerability in Apple Macos with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

This issue was addressed with improved state management of S/MIME encrypted emails. This issue is fixed in macOS Monterey 12.6.8. A S/MIME encrypted email may be inadvertently sent unencrypted.

Frequently asked questions

What is CVE-2023-40440?
This issue was addressed with improved state management of S/MIME encrypted emails. This issue is fixed in macOS Monterey 12.6.8. A S/MIME encrypted email may be inadvertently sent unencrypted.
How severe is CVE-2023-40440?
CVE-2023-40440 has a CVSS 3.x base score of 7.5, rated high 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 none.
Is CVE-2023-40440 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-2023-40440?
CVE-2023-40440 affects Apple Macos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-40440?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-40440 published?
CVE-2023-40440 was published on 2023-09-12 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Apple Macos

All CVEs affecting Apple Macos →