SoftEtherVPN is a an open-source cross-platform multi-protocol VPN Program. Versions 5.02.5184 to 5.02.5187 are vulnerable to NULL dereference in DeleteIPv6DefaultRouterInRA called by StorePacket. Before dereferencing, DeleteIPv6DefaultRouterInRA does not account for ParsePacket returning NULL, resulting in the program crashing. A patched version does not exist at this time.
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.