CVE-2026-43777Network attack vector

Remote service interruption via undisclosed invalid input

Published Jul 27, 2026 · Updated Jul 27, 2026

Input validation flaw in Apple macOS Sonoma before 14.8.8, Sequoia before 15.7.8, and Tahoe before 26.6 allows remote attackers to interrupt service. Apple identifies the affected locus only as Screen Sharing Server; the rejected input and the parsing operation performed on it are undisclosed. Exposure requires Screen Sharing or Remote Management to make the VNC-compatible service reachable, and the bounded consequence is interruption rather than data access or code execution.

CVSS severity7.5
High
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Input validation flaw in Apple macOS Sonoma before 14.8.8, Sequoia before 15.7.8, and Tahoe before 26.6 allows remote attackers to interrupt service. Apple identifies the affected locus only as Screen Sharing Server; the rejected input and the parsing operation performed on it are undisclosed. Exposure requires Screen Sharing or Remote Management to make the VNC-compatible service reachable, and the bounded consequence is interruption rather than data access or code execution.

The record

CVE
CVE-2026-43777
Published
Jul 27, 2026
Updated
Jul 27, 2026
Vendor
Apple
Product
macOS
Classifications
CWE-20, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <14.8.8
  2. Affected versionversion=0 <15.7.8
  3. Affected versionversion=0 <26.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Apple · macOSversion=0 <14.8.8; version=0 <15.7.8; version=0 <26.6

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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