Apple macOS Improper Authentication Vulnerability
Apple — macOS
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.
9.8
9.9%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- Aug 6, 2026
- Modified
- Aug 19, 2026
- Added to KEV
- Aug 18, 2026
- Federal patch due
- Aug 21, 2026
CISA required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Weakness classification
Proof-of-concept & exploitation references
3 foundWeaponization
Public repositories whose name or description references CVE-2026-65400, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
- panchocosil/CVE-2026-65400-poc★ 5
Read-only PoC for CVE-2026-65400 — macOS Screen Sharing (screensharingd) pre-auth SRP bypass giving root file read. Patched in macOS 26.6.1 / 15.7.9 / 14.8.9.
updated Sep 3, 2026
- acheong08/CVE-2026-65400★ 4
Apple MacOS Screen Sharing Arbitrary File read/write -> RCE
updated Sep 1, 2026
- HORKimhab/CVE-2026-65400★ 3
CVE-2026-65400
updated Aug 26, 2026
References
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 base score of 9.8 out of 10 (CVSS 3.1).
Is CVE-2026-65400 actively exploited in the wild?
Yes. CVE-2026-65400 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Aug 18, 2026, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2026-65400?
9.9% - meaning FIRST.org's EPSS model estimates a 9.9% probability this vulnerability will be exploited in the wild within 30 days (95% percentile among all scored CVEs).
Is there exploit tooling available for CVE-2026-65400?
We found 3 public GitHub repositories referencing CVE-2026-65400, though none matched a known Nuclei template or Metasploit module at last check. Review each one before relying on it - see the proof-of-concept section above.
What type of vulnerability is CVE-2026-65400?
CVE-2026-65400 is classified under CWE-287 (CWE-287 Improper Authentication).
Cross-checked against
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