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

published 2025-12-01 11 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-200023

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 7%
public exploits: 0; none known

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.

Patch / fix

fixed in 1

Gen Digital Avira Antivirus 8.3.70.98

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 11 mo ago (2025-12-01)

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% 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 Avira Antivirus

Classification

Weakness

CWE-122 Heap-based Buffer Overflow
CWE-125 Out-of-bounds Read

References

gendigital.com /us/en/contact-us/security-advisories/

Sources

CVE List CVE-2025-8351
NVD CVE-2025-8351

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.

Summary