I noticed this bug then did a fresh install in order to reproduce it.

1) fresh install, wizard creates admin account
(db attached as confluencedb.script.after-install)
2) logout and sign up
3) create a second user
(db attached as confluencedb.script.after-user2)
4) click "Profile" then "Edit Profile"
5) Receive the Exception below
(db attached as confluencedb.script.after-user2editprofile)
6) Going back to dashboard produces same Exception

java.lang.NullPointerException
at com.opensymphony.user.provider.hibernate.HibernateAccessProvider.listGroupsContainingUser(HibernateAccessProvider.java:137)
at com.opensymphony.user.User.getGroups(User.java:94)
at com.atlassian.confluence.security.DefaultSpacePermissionManager.hasPermission(DefaultSpacePermissionManager.java:133)
at sun.reflect.GeneratedMethodAccessor27.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.springframework.aop.interceptor.AbstractReflectionInvokerInterceptor.invoke(AbstractReflectionInvokerInterceptor.java:54)
at org.springframework.aop.framework.MethodInvocationImpl.proceed(MethodInvocationImpl.java:216)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:152)
at org.springframework.aop.framework.MethodInvocationImpl.proceed(MethodInvocationImpl.java:216)
at org.springframework.aop.framework.AopProxy.invoke(AopProxy.java:102)
at $Proxy8.hasPermission(Unknown Source)
at com.atlassian.confluence.ConfluenceActionSupport.isPermitted(ConfluenceActionSupport.java:100)
at com.atlassian.confluence.security.actions.PermissionCheckInterceptor.intercept(PermissionCheckInterceptor.java:37)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:169)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:37)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:169)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:37)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:169)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:37)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:169)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:37)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:169)
at com.opensymphony.xwork.interceptor.TimerInterceptor.intercept(TimerInterceptor.java:66)

at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:169)
at com.opensymphony.xwork.DefaultActionProxy.execute(DefaultActionProxy.java:116)
at com.opensymphony.webwork.dispatcher.ServletDispatcher.serviceAction(ServletDispatcher.java:181)
at com.opensymphony.webwork.dispatcher.ServletDispatcher.service(ServletDispatcher.java:161)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:129)
at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:61)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.seraph.filter.SecurityFilter.doFilter(SecurityFilter.java:161)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.seraph.filter.LoginFilter.doFilter(LoginFilter.java:181)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.confluence.setup.ConfluenceConfigurationFilter.doFilter(ConfluenceConfigurationFilter.java:73)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.confluence.setup.SessionInViewFilter.doFilter(SessionInViewFilter.java:37)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.util.profiling.filters.ProfilingFilter.doFilter(ProfilingFilter.java:148)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
....