Avira antivirus engine heap buffer OOB write when scanning a malformed POSIX tar archive
Priority LOW 35CWE-787Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00122 1st percentileScored 2026-11-07
Fix Fixed Avira Antivirus (Gen Digital): 8.3.27.12
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Gen Digital | Avira Antivirus | before 8.3.27.12 | 8.3.27.12 | Patch available | CNA |
- Avira Antivirus VendorGen Digital Affected before 8.3.27.12 Fixed in 8.3.27.12 Patch available CNA
Remediation
- Fix · CNA Avira Antivirus (Gen Digital) Fixed in 8.3.27.12
Timeline
- 2026-10-02 Threatist record created from CVE-2026-6676
- 2026-10-03 Alias added: GHSA-c89p-wq36-89h3
References
More Gen Digital vulnerabilities
- TI-2026-57223 Avast sandbox privilege escalation via unpreserved DACLs on virtualized files in aswSnx.sys CVSS 3.1HIGH 8.8
- TI-2026-22110 Avira Internet Security Optimizer TOCTOU CVSS 3.1HIGH 7.8
- TI-2026-22109 Avira Internet Security System Speedup Insecure Deserialization CVSS 3.1HIGH 7.8
- TI-2026-22108 Avira Internet Security Arbitrary File Deletion via Improper Link Resolution CVSS 3.1HIGH 7.8
- TI-2015-06072 Use-after-free vulnerability in the Update Manager service in Avira Management Console… CVSS 2.0HIGH 10.0
- TI-2023-18488 An issue was discovered in Avira Phantom VPN through 2.23.1 for macOS. CVSS 3.1HIGH 7.3
Sources
- CVE-2026-6676 · CVE Program
- CVE-2026-6676 · NVD
- FIRST EPSS
- GHSA-c89p-wq36-89h3 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences