Information dissemination rather than traditional routing is useful for many application domains in mobile ad hoc networks. Context-adaptive information dissemination is a special variant, which was originally designed for vehicular ad hoc networks (VANETs), but could also be used in other domains, for example, disaster management. In this work, we address the security of this dissemination scheme. The attack analysis shows weaknesses but also how the adaption to context already limits the impact of many attacks. We present and evaluate a sensor-based protection system helping to reduce the margin for attacks to a level of local disturbance, while the overall dissemination is not affected significantly any more. Copyright © 2008 John Wiley & Sons, Ltd.