CVE-2025-8351

Avira antivirus engine heap buffer OOB read when scanning a malformed file

Published Dec 1, 2025 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
Heap-based Buffer Overflow, Out-of-bounds Read vulnerability in Avira Antivirus engine when scanning a malformed file may allow Local Execution of Code or Denial-of-Service of the antivirus engine process.

This issue affects Avira Antivirus on Windows, macOS, and Linux for engine builds before 8.3.70.98.

Remediation

Vendor Solution

Upgrade to Avira scan engine build 8.3.70.98 or any later engine release. Builds at or above 8.3.70.98 include the fix.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Description 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. Heap-based Buffer Overflow, Out-of-bounds Read vulnerability in Avira Antivirus engine when scanning a malformed file may allow Local Execution of Code or Denial-of-Service of the antivirus engine process. This issue affects Avira Antivirus on Windows, macOS, and Linux for engine builds before 8.3.70.98.
Title Scanning a malformed file in Avast Antivirus 8.3.70.94 on MacOS may result in remote code execution Avira antivirus engine heap buffer OOB read when scanning a malformed file
Metrics cvssV3_1

{'score': 9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
First Time appeared Apple
Apple macos
Avast
Avast antivirus
Vendors & Products Apple
Apple macos
Avast
Avast antivirus
Type Values Removed Values Added
Title Scanning a malformed file in Avast Antivirus 8.3.70.94 on MacOS may result in remote code execution
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Weaknesses CWE-122
CWE-125
References
Metrics cvssV3_1

{'score': 9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
NLOK
Published
Updated
Jun 12, 2026, 10:32 PM
Reserved
Jul 30, 2025, 11:48 AM
Status
Deferred
Published
Dec 1, 2025, 4:15 PM
Modified
Jun 17, 2026, 10:06 AM