CVE-2026-80303: vulnerability in Gen Digital Avast Antivirus, Avast One, Avast…
Avast WFP stream parser integer underflow causes system crash
Published
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0Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Track
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.
Affected products
Gen Digital · Avast Antivirus, Avast One, Avast Premium Security, Avast UltimateGen Digital · AVG Antivirus Free, AVG Internet Security, AVG UltimateGen Digital · Norton Antivirus Plus, Norton 360 Standard, Norton 360 Deluxe, Norton 360 AdvancedRelated CVEs — Gen Digital Avast Antivirus, Avast One, Avast…
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