A vulnerability in the SRX Series Service Gateway allows deleted dynamic VPN users to establish dynamic VPN connections until the device is rebooted. A deleted dynamic VPN connection should be immediately disallowed from establishing new VPN connections. Due to an error in token caching, deleted users are allowed to connect once a previously successful dynamic VPN connection has been established. A reboot is required to clear the cached authentication token. Affected releases are Junos OS on SRX Series: 12.3X48 versions prior to 12.3X48-D75; 15.1X49 versions prior to 15.1X49-D150; 17.3 versions prior to 17.3R3; 17.4 versions prior to 17.4R2; 18.1 versions prior to 18.1R3; 18.2 versions prior to 18.2R2.