What is the CVSS score of CVE-2025-8351?

CVE-2025-8351 has a CVSS 3.1 base score of 7.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of Apple are affected by CVE-2025-8351?

Avast Antivirus for macOS contains a critical heap-based buffer overflow vulnerability (CVE-2025-8351, CVSS 9.0) that allows local attackers to execute arbitrary code or crash the antivirus engine by…. A patch is available.

How to fix or mitigate CVE-2025-8351?

Within 24 hours: Identify all macOS systems running Avast Antivirus versions 8.3.70.94 through 8.3.70.97 using inventory tools. Within 7 days: Deploy Avast Antivirus version 8.3.70.98 or later to all affected macOS endpoints through your management console or software update mechanism. Within 30 days: Conduct post-patch verification scans on all updated systems and document remediation completion in your vulnerability management system.

Apple CVE-2025-8351

EUVD-2025-200023 HIGH

Heap-based Buffer Overflow (CWE-122)

2025-12-01 security@nortonlifelock.com

Heap Overflow Buffer Overflow Apple

7.8

CVSS 3.1 · Vendor: nortonlifelock

Severity by source

Vendor (nortonlifelock) PRIMARY

7.8 HIGH

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

Primary rating from Vendor (nortonlifelock) · only source for this CVE.

CVSS VectorVendor: nortonlifelock

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

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Severity Changed

Jun 12, 2026 - 23:22 NVD

CRITICAL HIGH

CVSS changed

Jun 12, 2026 - 23:22 NVD

9.0 (CRITICAL) 7.8 (HIGH)

Analysis Updated

Apr 16, 2026 - 05:50 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

8.3.70.98

EUVD ID Assigned

Mar 15, 2026 - 13:34 euvd

EUVD-2025-200023

Analysis Generated

Mar 15, 2026 - 13:34 vuln.today

CVE Published

Dec 01, 2025 - 16:15 nvd

CRITICAL 9.0

DescriptionCVE.org

Heap-based Buffer Overflow, Out-of-bounds Read vulnerability in Avast Antivirus on MacOS when scanning a malformed file may allow Local Execution of Code or Denial-of-Service of the anitvirus engine process.This issue affects Antivirus: from 8.3.70.94 before 8.3.70.98.