CVE-2026-6676: CWE-787 Out-of-bounds Write in Gen Digital Avira Antivirus
CVE-2026-6676 is a heap buffer out-of-bounds write vulnerability in the Avira Antivirus engine that occurs when scanning a malformed POSIX tar archive. This flaw may allow local attackers to execute code or cause a denial-of-service condition in the antivirus engine process. The vulnerability affects Avira Antivirus engine builds prior to version 8.3.27.12 on Windows, macOS, and Linux platforms. The vulnerability has a high severity rating with a CVSS score of 7.8.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-6676) involves a heap buffer out-of-bounds write in the Avira Antivirus engine triggered by scanning a specially crafted POSIX tar archive. Successful exploitation could lead to local code execution or denial-of-service impacting the antivirus engine process. The issue affects Avira Antivirus engine builds before 8.3.27.12 across Windows, macOS, and Linux. No official patch or remediation level has been confirmed as of the published date. There are no known exploits in the wild.
Potential Impact
An attacker with local access could exploit this vulnerability by providing a malformed POSIX tar archive to the Avira Antivirus engine, potentially resulting in arbitrary code execution or crashing the antivirus process, leading to denial-of-service. This could undermine the security posture of the affected system by disabling or compromising the antivirus protection.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, avoid scanning untrusted or malformed POSIX tar archives with affected versions of Avira Antivirus engine. Monitor vendor communications for updates regarding patches or workarounds.
CVE-2026-6676: CWE-787 Out-of-bounds Write in Gen Digital Avira Antivirus
Description
CVE-2026-6676 is a heap buffer out-of-bounds write vulnerability in the Avira Antivirus engine that occurs when scanning a malformed POSIX tar archive. This flaw may allow local attackers to execute code or cause a denial-of-service condition in the antivirus engine process. The vulnerability affects Avira Antivirus engine builds prior to version 8.3.27.12 on Windows, macOS, and Linux platforms. The vulnerability has a high severity rating with a CVSS score of 7.8.
CVSS v3.1
Score 7.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-6676) involves a heap buffer out-of-bounds write in the Avira Antivirus engine triggered by scanning a specially crafted POSIX tar archive. Successful exploitation could lead to local code execution or denial-of-service impacting the antivirus engine process. The issue affects Avira Antivirus engine builds before 8.3.27.12 across Windows, macOS, and Linux. No official patch or remediation level has been confirmed as of the published date. There are no known exploits in the wild.
Potential Impact
An attacker with local access could exploit this vulnerability by providing a malformed POSIX tar archive to the Avira Antivirus engine, potentially resulting in arbitrary code execution or crashing the antivirus process, leading to denial-of-service. This could undermine the security posture of the affected system by disabling or compromising the antivirus protection.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, avoid scanning untrusted or malformed POSIX tar archives with affected versions of Avira Antivirus engine. Monitor vendor communications for updates regarding patches or workarounds.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GEN
- Date Reserved
- 2026-04-20T14:46:06.355Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a2c8e3ee617e2d834d0f248
Added to database: 6/12/2026, 10:54:54 PM
Last enriched: 6/12/2026, 11:09:19 PM
Last updated: 6/13/2026, 1:38:02 AM
Views: 6
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