Integer Underflow Vulnerability
Source GCVE Database
Not known to be exploited.
Data as of 6 Nov 2026, 19:33 UTC
Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or noneExploitation evidence
Disclosed: evidence found.
CVE published 6 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Gen DigitalAvast Antivirus, Avast One, Avast Premium Security, Avast Ultimate | Affected
| Fixed in– |
| Gen DigitalAVG Antivirus Free, AVG Internet Security, AVG Ultimate | Affected
| Fixed in– |
| Gen DigitalNorton Antivirus Plus, Norton 360 Standard, Norton 360 Deluxe, Norton 360 Advanced | Affected
| Fixed in– |
AI-suggested
Users should monitor vendor advisories for updates. Until a fix is released, consider limiting exposure of the affected filtering interfaces to untrusted network traffic and avoid processing untrusted data through the vulnerable component.
Description
An integer underflow vulnerability exists in the Avast Windows Filtering Platform (WFP) stream parser on Windows. This flaw allows denial of service by causing a system crash through a kernel panic. The vulnerability arises from improper validation of input stream sizes during length calculation for packet fragment reassembly, leading to an underflow and subsequent memory allocation or buffer access with an incorrect large size. It can be triggered remotely via network traffic or locally via crafted data to the filtering interface.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80303 (opens in a new tab)
- support.avast.com/en-us/article/Update-Antivirus (opens in a new tab)
- support.avg.com/SupportArticleView?l=en&urlname=Update-AVG-Antivirus (opens in a new tab)
- support.norton.com/sp/en/us/home/current/solutions/v20240108175512167 (opens in a new tab)
- gendigital.com/us/en/contact-us/security-advisories (opens in a new tab)