Out-of-bounds Read in Avast Antivirus

CVE-2025-10101

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (6.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 6.6% 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-2025-10101: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-10101?
CVE-2025-10101 is a high-severity vulnerability in Avast Antivirus, classified under Out-of-bounds Read. CVSS score: 7.8/10. Published 2025-12-01.
How severe is CVE-2025-10101?
High severity. CVSS v3 base score is 7.8 out of 10.