CVE-2026-20639
Received Received - Intake
Integer Overflow in macOS String Processing Causes Heap Corruption

Publication date: 2026-03-25

Last updated on: 2026-03-25

Assigner: Apple Inc.

Description
An integer overflow was addressed with improved input validation. This issue is fixed in macOS Sequoia 15.7.5, macOS Sonoma 14.8.5, macOS Tahoe 26.3. Processing a maliciously crafted string may lead to heap corruption.
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Meta Information
Published
2026-03-25
Last Modified
2026-03-25
Generated
2026-06-16
AI Q&A
2026-03-25
EPSS Evaluated
2026-06-15
NVD
CVE-2026-20639
EUVD
EUVD-2026-15043
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
apple macos From 26.0 (inc) to 26.3 (exc)
apple macos From 14.0 (inc) to 14.8.5 (exc)
apple macos From 15.0 (inc) to 15.7.5 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-190 The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
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Executive Summary

This vulnerability is an integer overflow issue that occurs due to insufficient input validation. Specifically, processing a maliciously crafted string can trigger this overflow, which may lead to heap corruption.

Impact Analysis

The impact of this vulnerability is that an attacker could exploit the integer overflow by providing a specially crafted string, potentially causing heap corruption. This could lead to unexpected behavior, crashes, or possibly allow further exploitation depending on the context.

Compliance Impact

I don't know

Detection Guidance

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Mitigation Strategies

To mitigate this vulnerability, update your macOS system to one of the fixed versions: macOS Sequoia 15.7.5, macOS Sonoma 14.8.5, or macOS Tahoe 26.3.

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