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PatchSiren cyber security CVE debrief

CVE-2026-6676 Gen Digital CVE debrief

A heap buffer out-of-bounds write vulnerability exists in the Avira Antivirus engine when scanning a malformed POSIX tar archive. This issue, tracked as CVE-2026-6676, may allow for Local Execution of Code or Denial-of-Service of the antivirus engine process. The vulnerability affects Avira Antivirus on Windows, macOS, and Linux for engine builds before 8.3.27.12. The CVSS score for this vulnerability is 7.8, indicating a HIGH severity level.

Vendor
Gen Digital
Product
Avira Antivirus
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-12
Original CVE updated
2026-06-15
Advisory published
2026-06-12
Advisory updated
2026-06-15

Who should care

Users of Avira Antivirus on Windows, macOS, and Linux with engine builds before 8.3.27.12 should be aware of this vulnerability and take necessary actions to mitigate the risk.

Technical summary

The vulnerability is caused by a heap buffer out-of-bounds write issue in the Avira Antivirus engine when processing a malformed POSIX tar archive. This could lead to Local Execution of Code or Denial-of-Service of the antivirus engine process.

Defensive priority

HIGH

Recommended defensive actions

  • Update Avira Antivirus engine to build 8.3.27.12 or later.
  • Ensure that all systems running Avira Antivirus are running the latest engine version.

Evidence notes

The CVE record and details were obtained from official sources.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-6676 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-6676

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-6676 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-6676

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.