Apple macOS Improper Authentication
What to do
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.
CISA deadline 2026-08-21 · passed 20 days ago · applies to US federal civilian agencies; used elsewhere as a reference SLA
What happened
Apple macOS contains an improper authentication vulnerability that could allow an attacker on the network to authenticate to Screen Sharing without valid credentials.
Who is affected
Apple macOS. Affected version ranges are listed in the vendor advisory and the NVD entry linked under Sources.
Weakness class: CWE-287.
Timeline
- Added to CISA KEVExploitation in the wild confirmed by CISA
- CISA remediation deadlinepassed 20 days ago
Sources
- NVD entry for CVE-2026-65400 nvd.nist.gov/vuln/detail/CVE-2026-65400
- CISA Known Exploited Vulnerabilities catalog www.cisa.gov/known-exploited-vulnerabilities-catalog
- support.apple.com support.apple.com/en-us/148170
- support.apple.com support.apple.com/en-us/148171
- support.apple.com support.apple.com/en-us/148172
- cisa.gov www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- cisa.gov www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- nvd.nist.gov nvd.nist.gov/vuln/detail/CVE-2026-65400