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Fencer Vulns
high 7.8

CVE-2025-10101 json

Avast antivirus heap buffer OOB read when scanning a malformed Mach-O file

published 2025-12-01 11 mo ago modified 2026-09-26 44 d ago also EUVD-2025-200024

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits
0
none known

Summary

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.

Patch / fix

  • Gen Digital Avast Antivirus 25090300
  • Gen Digital AVG Antivirus 25090300
  • Gen Digital Norton Antivirus 25090300
  • Gen Digital Avast One 25090300
  • Gen Digital Avast Business Antivirus 25090300

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
11 mo ago

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • Gen Digital Avast Antivirus
  • Gen Digital AVG Antivirus
  • Gen Digital Norton Antivirus
  • Gen Digital Avast One
  • Gen Digital Avast Business Antivirus

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.