TI-2026-76707 Aliases CVE-2026-86981 GHSA-w558-29wr-g4fh

Out-of-bounds write in Apple macOS lets apps crash the system

LOW 24CWE-787Published 2026-10-20 · Updated 2026-10-26

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.

Summary

Apple macOS before 15.8 and macOS before 26.7 contain an out-of-bounds write flaw (CWE-787) that improved bounds checking addresses. A local app with low privileges can cause unexpected system termination, which affects availability.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.8, macOS Tahoe 26.7. An app may be able to cause unexpected system termination.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00142 3rd percentileScored 2026-11-07

Fix Fixed macOS (Apple): 15.8, 26.7

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Apple	macOS	before 15.8; before 26.7	15.8, 26.7	Patch available	CNA

macOS VendorApple Affected before 15.8; before 26.7 Fixed in 15.8, 26.7 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:o:apple:macos::::::::	15.0 to before 15.8; 26.0 to before 26.7	Vulnerable	Apple

cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:* Versions 15.0 to before 15.8; 26.0 to before 26.7 Vulnerable ·Apple

Remediation

Update to macOS Sequoia 15.8 or macOS Tahoe 26.7, which fix this issue.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Fix · CNA macOS (Apple) Fixed in 15.8, 26.7

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2026-10-20
Apple macOS 15.8, 26.7
4 records Highest priority Priority LOW 4 LOW
Other records, highest priority first
- TI-2026-76653 Apple macOS flaw lets apps gain higher privilegesPriority LOW 35
- TI-2026-76693 Apple iOS, iPadOS and macOS out-of-bounds write causes system terminationPriority LOW 24
- TI-2026-76680 Missing authorization in Apple macOS lets admins modify System KeychainPriority LOW 19
Show all 4 records →

Timeline

2026-10-20 Threatist record created from CVE-2026-86981
2026-10-20 CVSS score added · CISA ADP
2026-10-20 Weakness changed · CISA ADP
2026-10-20 CISA SSVC decision points changed
2026-10-20 Alias added: GHSA-w558-29wr-g4fh

References

Advisory 2

TI-2026-46583 Improper authentication in Apple macOS KEVCVSS 3.1CRITICAL 9.8
TI-2025-28008 Out-of-bounds write in Apple iOS and iPadOS KEVCVSS 3.1CRITICAL 10.0
TI-2025-22441 Apple iOS and iPadOS: An attacker with arbitrary read and write capability may be able to… KEVCVSS 3.1CRITICAL 9.8
TI-2025-22440 Memory corruption in Apple iOS and iPadOS KEVCVSS 3.1CRITICAL 9.8
TI-2025-17951 Out-of-bounds write in Apple Safari KEVCVSS 3.1CRITICAL 10.0
TI-2025-17847 Use after free in Apple iOS and iPadOS KEVCVSS 3.1CRITICAL 10.0

See all 3490 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences