Apple macOS up to 15.7/26/26.6 integer underflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.2$0-$5k3.12

Summaryinfo

A vulnerability was found in Apple macOS up to 15.7/26/26.6. It has been declared as critical. Affected by this issue is some unknown functionality. The manipulation results in integer underflow. This vulnerability is known as CVE-2026-86871. It is possible to launch the attack remotely. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Apple macOS up to 15.7/26/26.6. It has been classified as critical. Affected is some unknown processing. The manipulation with an unknown input leads to a integer underflow vulnerability. CWE is classifying the issue as CWE-191. The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result. This is going to have an impact on availability. CVE summarizes:

An integer underflow was addressed with improved input validation. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. An attacker with control of a network file server may be able to cause unexpected system termination.

The advisory is available at support.apple.com. This vulnerability is traded as CVE-2026-86871 since 09/08/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/20/2026).

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

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.2

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
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: Integer underflow
CWE: CWE-191 / CWE-189
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

09/08/2026 CVE reserved
10/20/2026 +42 days Advisory disclosed
10/20/2026 +0 days VulDB entry created
10/20/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: apple.com

Advisory: support.apple.com
Status: Confirmed

CVE: CVE-2026-86871 (🔒)
GCVE (CVE): GCVE-0-2026-86871
GCVE (VulDB): GCVE-100-422610
scip Labs: https://www.scip.ch/en/?labs.20180712

Entryinfo

Created: 10/20/2026 03:36
Changes: 10/20/2026 03:36 (55)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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