CVE-2026-84509
Apple macOS SMB Out-of-Bounds Read
Description
An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. Connecting to a malicious SMB server may lead to unexpected system termination.
INFO
Published Date :
Sept. 14, 2026, 9:17 p.m.
Last Modified :
Sept. 17, 2026, 4:56 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Apply security updates for macOS.
- Implement strict input validation.
- Ensure SMB server connections are validated.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-84509.
| URL | Resource |
|---|---|
| https://support.apple.com/en-us/149035 | Release Notes Vendor Advisory |
| https://support.apple.com/en-us/149042 | Release Notes Vendor Advisory |
| https://support.apple.com/en-us/149043 | Release Notes Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-84509 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-84509
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-84509 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-84509 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Sep. 17, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:* versions from (including) 15.0 up to (excluding) 15.8 *cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:* versions from (including) 26.0 up to (excluding) 26.7 Added Reference Type Apple Inc.: https://support.apple.com/en-us/149035 Types: Release Notes, Vendor Advisory Added Reference Type Apple Inc.: https://support.apple.com/en-us/149042 Types: Release Notes, Vendor Advisory Changed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://support.apple.com/en-us/149035 Types: Vendor Advisory nvd-ai-agent-0.3.0-gemma-4-31B-it: https://support.apple.com/en-us/149035 Types: Release Notes, Vendor Advisory, Vendor Advisory Changed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://support.apple.com/en-us/149042 Types: Vendor Advisory nvd-ai-agent-0.3.0-gemma-4-31B-it: https://support.apple.com/en-us/149042 Types: Release Notes, Vendor Advisory, Vendor Advisory Added Reference Type Apple Inc.: https://support.apple.com/en-us/149043 Types: Release Notes, Vendor Advisory Changed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://support.apple.com/en-us/149043 Types: Vendor Advisory nvd-ai-agent-0.3.0-gemma-4-31B-it: https://support.apple.com/en-us/149043 Types: Release Notes, Vendor Advisory, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 17, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Added CWE CWE-125 Added SSVC {'id': 'CVE-2026-84509', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-17T15:08:59.116627Z'} -
New CVE Received by [email protected]
Sep. 14, 2026
Action Type Old Value New Value Added Description An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. Connecting to a malicious SMB server may lead to unexpected system termination. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/84xxx/CVE-2026-84509.json">CVE-2026-84509</a> Added Reference https://support.apple.com/en-us/149035 Added Reference https://support.apple.com/en-us/149042 Added Reference https://support.apple.com/en-us/149043