CVE-2026-6676 Avira antivirus engine heap buffer OOB write when scanning a malformed POSIX tar archive
Local attackers can trigger code execution or denial of service in Avira Antivirus by providing a malformed POSIX tar archive.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-6676?
CVE-2026-6676 is a high-severity memory corruption vulnerability in Gen Digital Avira Antivirus, published on 12 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
Heap buffer out-of-bounds write vulnerability in Avira Antivirus engine when scanning a malformed POSIX tar archive 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 8.3.27.12.
Weakness: CWE-787
Which versions are affected by CVE-2026-6676?
How do I fix CVE-2026-6676?
No fix has been published for CVE-2026-6676 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-6676 being exploited?
There is no known exploitation of CVE-2026-6676 in the wild and no public exploit code.
Sources
Also known as GHSA-c89p-wq36-89h3.