CVE-2023-35838: Wireguard

Medium severity, CVSS 5.7. EPSS: 0.7% chance of exploitation in the next 30 days.

The WireGuard client 0.5.3 on Windows insecurely configures the operating system and firewall such that traffic to a local network that uses non-RFC1918 IP addresses is blocked. This allows an adversary to trick the victim into blocking IP traffic to selected IP addresses and services even while the VPN is enabled. NOTE: the tunnelcrack.mathyvanhoef.com website uses this CVE ID to refer more generally to "LocalNet attack resulting in the blocking of traffic" rather than to only WireGuard.

Affected products

• Wireguard Wireguard: version 0.5.3 only

Published 2023-08-09. Last modified 2026-06-17.