Apple macOS up to 15.7/26/26.6 SMB Client memory corruption

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.3$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Apple macOS up to 15.7/26/26.6. Affected by this issue is some unknown functionality of the component SMB Client. Executing a manipulation can lead to memory corruption. This vulnerability appears as CVE-2026-84509. The attack may be performed from remote. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Apple macOS up to 15.7/26/26.6 and classified as critical. This vulnerability affects some unknown functionality of the component SMB Client. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at support.apple.com. This vulnerability was named CVE-2026-84509 since 09/01/2026. The exploitation appears to be easy. The attack can be initiated remotely. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/15/2026).

Upgrading to version 15.8, 26.7 or 27 eliminates this vulnerability.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: macOS 15.8/26.7/27

Timelineinfo

09/01/2026 CVE reserved
09/14/2026 +13 days VulDB entry created
09/15/2026 +0 days Advisory disclosed
09/15/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: apple.com

Advisory: support.apple.com
Status: Confirmed

CVE: CVE-2026-84509 (🔒)
GCVE (CVE): GCVE-0-2026-84509
GCVE (VulDB): GCVE-100-403888
scip Labs: https://www.scip.ch/en/?labs.20180712

Entryinfo

Created: 09/15/2026 00:53
Changes: 09/15/2026 00:53 (56)
Complete: 🔍
Cache ID: 216::103

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