How severe is CVE-2026-65400?

CVE-2026-65400 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-2026-65400 being actively exploited?

Yes. CVE-2026-65400 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-08-18, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2026-65400?

CVE-2026-65400 affects Apple Macos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-65400?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

When was CVE-2026-65400 published?

CVE-2026-65400 was published on 2026-08-06 and last updated on 2026-08-19.

CVE-2026-65400

CVE-2026-65400 is a critical-severity vulnerability in Apple Macos with a CVSS 3.x base score of 9.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-08-18). The underlying weakness is classified as CWE-287.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Yes — listed in CISA KEV (added 2026-08-18)
Weakness: CWE-287
Affected product: Apple Macos
Published: 2026-08-06
Last modified: 2026-08-19

Description

An authentication issue was addressed with improved state management. This issue is fixed in macOS Sequoia 15.7.9, macOS Sonoma 14.8.9, macOS Tahoe 26.6.1. An attacker on the network may be able to authenticate to Screen Sharing without valid credentials.

Frequently asked questions

What is CVE-2026-65400?: An authentication issue was addressed with improved state management. This issue is fixed in macOS Sequoia 15.7.9, macOS Sonoma 14.8.9, macOS Tahoe 26.6.1. An attacker on the network may be able to authenticate to Screen Sharing without valid credentials.
How severe is CVE-2026-65400?: CVE-2026-65400 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-2026-65400 being actively exploited?: Yes. CVE-2026-65400 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-08-18, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2026-65400?: CVE-2026-65400 affects Apple Macos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-65400?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
When was CVE-2026-65400 published?: CVE-2026-65400 was published on 2026-08-06 and last updated on 2026-08-19.

References

Affected products (1)

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

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