CVE-2026-84509: Connecting to a malicious SMB server may lead to unexpected system termination in Apple macOS
A vulnerability in Apple macOS allows connecting to a malicious SMB server to cause unexpected system termination due to an out-of-bounds read. This issue has been fixed in macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7 by improving bounds checking.
AI Analysis
Technical Summary
CVE-2026-84509 is an out-of-bounds read vulnerability in Apple macOS SMB client code. When connecting to a malicious SMB server, the system may perform an out-of-bounds read leading to unexpected system termination (crash). Apple addressed this issue by improving bounds checking in the affected components. The vulnerability affects macOS versions prior to Golden Gate 27, Sequoia 15.8, and Tahoe 26.7.
Potential Impact
Successful exploitation of this vulnerability may cause the affected macOS system to terminate unexpectedly (crash) when connecting to a malicious SMB server. There is no indication of code execution or data disclosure in the provided data.
Mitigation Recommendations
Apple has released fixes in macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7. Users and administrators should update to these versions or later to remediate this vulnerability.
CVE-2026-84509: Connecting to a malicious SMB server may lead to unexpected system termination in Apple macOS
Description
A vulnerability in Apple macOS allows connecting to a malicious SMB server to cause unexpected system termination due to an out-of-bounds read. This issue has been fixed in macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7 by improving bounds checking.
Affected software
Apple
macOS
pkg:github/apple/macosRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-84509 is an out-of-bounds read vulnerability in Apple macOS SMB client code. When connecting to a malicious SMB server, the system may perform an out-of-bounds read leading to unexpected system termination (crash). Apple addressed this issue by improving bounds checking in the affected components. The vulnerability affects macOS versions prior to Golden Gate 27, Sequoia 15.8, and Tahoe 26.7.
Potential Impact
Successful exploitation of this vulnerability may cause the affected macOS system to terminate unexpectedly (crash) when connecting to a malicious SMB server. There is no indication of code execution or data disclosure in the provided data.
Mitigation Recommendations
Apple has released fixes in macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7. Users and administrators should update to these versions or later to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apple
- Date Reserved
- 2026-09-01T21:13:17.748Z
- State
- PUBLISHED
Threat ID: 6aa8610255bf5e2cf59d2837
Added to database: 09/14/2026, 21:02:58 UTC
Last enriched: 09/14/2026, 22:29:52 UTC
Last updated: 09/15/2026, 05:01:22 UTC
Views: 3
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