Integer overflow in Avast Antivirus

CVE-2025-3500

Integer Overflow or Wraparound vulnerability in Avast Antivirus (25.1.981.6) on Windows allows Privilege Escalation.This issue affects Antivirus: from 25.1.981.6 before 25.3.

Vulnerability class: Integer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (37.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-3500: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-3500?
CVE-2025-3500 is a critical-severity vulnerability in Avast Antivirus, classified under Integer Overflow or Wraparound. CVSS score: 9.0/10. Published 2025-12-01.
How severe is CVE-2025-3500?
Critical severity. CVSS v3 base score is 9.0 out of 10.
Is CVE-2025-3500 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.