CVE-2026-80303 (GCVE-0-2026-80303)

Vulnerability from cvelistv5 – Published: 2026-11-06 15:59 – Updated: 2026-11-10 19:11
VLAI
Title
Avast WFP stream parser integer underflow causes system crash
Summary
An integer underflow vulnerability in the Avast Windows Filtering Platform (WFP) stream parser on Windows allows denial of service by causing a system crash. The WFP callout driver processes network stream data and computes length values for packet fragment reassembly. The length calculation does not properly validate input stream sizes against expected boundaries. When processing specially crafted input, the length computation underflows, resulting in allocation or buffer access with an extremely large wrapped-around size value. The underflow can be triggered remotely via network traffic destined for the filtered port, or locally via crafted data provided to the filtering interface. The resulting memory allocation failure or out-of-bounds access causes a kernel panic and system crash.
Severity
6.2 (Medium)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-11-10 19:10 UTC
CWE
  • CWE-191 - Integer Underflow (Wrap or Wraparound)
  • CWE-248 - Uncaught Exception
Assigner
GEN CNA under the mitre root
CNA scorecard B 75/100 over 24 records in the last 180 days details
References
Impacted products
Credits
Teng Zheng Wang by VulnGuard Labs
Show details on NVD website
To clipboard 

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