CVEs / CVE-2026-65400
CVE-2026-65400: Apple macOS Improper Authentication Vulnerability
- Known exploited in the CISA KEV catalog since 18 Aug 2026
- critical 9.8 CVSS 3.1 (from the CNA)
- EPSS 1.72% chance of exploitation in the next 30 days, higher than 77% of CVEs (30 Oct 2026)
- Last changed at its sources
Are you affected? Check your servers with Stackurity: it lists the software on each server and the vulnerabilities to fix first.
Check your servers with Stackurity Already using Stackurity? Search for CVE-2026-65400
Summary
Apple macOS contains an improper authentication vulnerability that could allow an attacker on the network to authenticate to Screen Sharing without valid credentials.
Description
An authentication issue was addressed with improved state management. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.7.9, macOS Sonoma 14.8.9, macOS Tahoe 26.6.1, macOS Tahoe 26.7. An attacker on the network may be able to authenticate to Screen Sharing without valid credentials.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Apple macOS | before 14.8.9 | 14.8.9 |
| Apple macOS | before 15.7.9 | 15.7.9 |
| Apple macOS | before 26.6.1 | 26.6.1 |
| Apple macOS | before 26.7 | 26.7 |
| Apple macOS | before 27 | 27 |
Exploitation
| In CISA KEV since | 18 Aug 2026 |
|---|---|
| Due date for US federal agencies | 21 Aug 2026 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by the CNA (134c704f-9b21-4f2e-91b3-4a467353bcc0) |
|---|---|
| Weakness | CWE-287 |
References
- CVE-2026-65400 on NVD
- CVE-2026-65400 in the CISA KEV catalog
- https://support.apple.com/en-us/148170 (cited by CISA)
- https://support.apple.com/en-us/148171 (cited by CISA)
- https://support.apple.com/en-us/148172 (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- https://support.apple.com/en-us/148170 Release Notes, Vendor Advisory
- https://support.apple.com/en-us/148171 Release Notes, Vendor Advisory
- https://support.apple.com/en-us/148172 Release Notes, Vendor Advisory
- https://support.apple.com/en-us/149035 Release Notes, Vendor Advisory
- https://support.apple.com/en-us/149042 Release Notes, Vendor Advisory
- http://seclists.org/fulldisclosure/2026/Aug/36 Mailing List
- http://seclists.org/fulldisclosure/2026/Aug/37 Broken Link
- https://advisories.ncsc.nl/2026/ncsc-2026-0280.html Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-65400 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.