Avast antivirus heap buffer OOB read when scanning a malformed Mach-O file
Published Dec 1, 2025
7.8
HIGHCVSS 3.1
EPSS 0.18%
Description
Heap buffer out-of-bounds read vulnerability in Avast Antivirus when scanning a malformed Mach-O file may allow Local Execution of Code or Denial-of-Service of the antivirus process.
This issue affects Avast Antivirus, AVG Antivirus, Norton Antivirus, Avast One, and Avast Business Antivirus on Windows, macOS, and Linux for virus definition builds before VPS 25090300.
The affected scanning logic is delivered through a shared Gen Digital virus definition update stream. The same stream feeds the consumer antivirus products listed in this advisory and other Gen Digital products that embed the same engine. Mitigation flows through this update channel; installations at or above the listed build are not vulnerable regardless of which product consumes the stream.
Affected products
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- Version 0StatusaffectedConstraints<25090300
- Version
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- Version 0StatusaffectedConstraints<25090300
- Version
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- Version 0StatusaffectedConstraints<25090300
- Version
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- Version 0StatusaffectedConstraints<25090300
- Version
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- Version 0StatusaffectedConstraints<25090300
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Gen Digital | AVG Antivirus | affected |
| ||||||
| Gen Digital | Avast Antivirus | affected |
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| Gen Digital | Avast Business Antivirus | affected |
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| Gen Digital | Avast One | affected |
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| Gen Digital | Norton Antivirus | affected |
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No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
Vendor solution
Install virus definitions VPS 25090300 or any later virus-definition update. All builds at or above VPS 25090300 include the fix; staying current on definitions is required.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
TotalDecision
n/aAssessed Dec 2, 2025 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
Score over time
2025–2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 0.18% (0.00179) | 6.71th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.14% (0.00145) | 4.10th | v5 (v2026.06.15) |
| Dec 2, 2025 | 0.01% (0.00014) | 1.92th | v4 (v2025.03.14) |
References (1)
Change history (0)
No recorded changes yet.