What is the CVSS score of CVE-2026-28891?

CVE-2026-28891 has a CVSS 3.1 base score of 8.1 (High). CVSS vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of macOS are affected by CVE-2026-28891?

CVE-2026-28891 is a HIGH severity sandbox escape vulnerability affecting macOS Sequoia, Sonoma, and Tahoe that allows locally-installed applications to break confinement and access system resources…. A patch is available.

How to fix or mitigate CVE-2026-28891?

Within 24 hours: Inventory all macOS systems running Sequoia 15.7.4 or earlier, Sonoma 14.8.4 or earlier, and Tahoe 26.3 or earlier; alert macOS users not to install untrusted applications. Within 7 days: Restrict local application execution policies where feasible and monitor for suspicious sandbox-escape indicators (unusual system call sequences, out-of-process resource access). Within 30 days: Apply vendor patches immediately upon release; if no patch is available within 30 days, evaluate mandatory upgrade to the next patched macOS point release or implement application allow-listing on high-risk systems.

macOS CVE-2026-28891

EUVD-2026-15169 HIGH

Race Condition (CWE-362)

2026-03-25 apple

GHSA-w5rf-7qr8-hm2m

Apple Race Condition Information Disclosure macOS

8.1

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.1 HIGH

AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack Vector

Local

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Updated

Apr 16, 2026 - 06:16 EUVD-patch-fix

executive_summary

Re-analysis Queued

Apr 16, 2026 - 05:29 backfill_euvd_patch

patch_released

Patch available

Apr 16, 2026 - 05:29 EUVD

15.7.5,14.8.5,26.4

EUVD ID Assigned

Mar 25, 2026 - 01:00 euvd

EUVD-2026-15169

Analysis Generated

Mar 25, 2026 - 01:00 vuln.today

CVE Published

Mar 25, 2026 - 00:32 nvd

HIGH 8.1

DescriptionCVE.org

A race condition was addressed with additional validation. This issue is fixed in macOS Sequoia 15.7.5, macOS Sonoma 14.8.5, macOS Tahoe 26.4. An app may be able to break out of its sandbox.

AnalysisAI

Sandbox escape vulnerability in macOS (Sequoia 15.7.4 and earlier, Sonoma 14.8.4 and earlier, Tahoe 26.3 and earlier) allows locally-installed applications to break out of their sandbox restrictions through a race condition. An attacker with the ability to run an application on an affected system could exploit this to gain unauthorized access outside the application's intended security boundaries. No patch is currently available for this HIGH severity vulnerability (CVSS 8.1).

Technical ContextAI

This vulnerability is rooted in a race condition (CWE classification implied by vendor description) within macOS sandbox enforcement mechanisms. Race conditions occur when multiple processes or threads access shared resources without proper synchronization, creating a time-of-check-to-time-of-use (TOCTOU) vulnerability window. The affected product, macOS (CPE: cpe:2.3:a:apple:macos:*:*:*:*:*:*:*:*), relies on sandbox kernel extensions and userspace validation to restrict application capabilities. The race condition exists in the validation logic that enforces sandbox boundaries, allowing an attacker to bypass these restrictions by carefully timing operations between the validation check and actual enforcement. Apple's fix involves adding additional validation layers to eliminate the race condition window, suggesting a multi-stage enforcement mechanism was previously insufficient.

RemediationAI

Immediately upgrade affected macOS systems to the patched versions: macOS Sequoia to 15.7.5 or later, macOS Sonoma to 14.8.5 or later, or macOS Tahoe to 26.4 or later. Consult Apple's official security advisories at https://support.apple.com/en-us/126794 (Tahoe), https://support.apple.com/en-us/126795 (Sonoma), and https://support.apple.com/en-us/126796 (Sequoia) for detailed patch deployment instructions and build numbers. While patching is the primary remediation, organizations that cannot immediately patch should implement application whitelisting policies to restrict execution of untrusted or unverified applications, disable unnecessary user-facing services, and monitor system logs for sandbox-related errors or unexpected privilege escalations. Users should also avoid running applications from unknown or untrusted sources until patching is completed.