src/http/ngx_http_parse.c in nginx (aka Engine X) 0.1.0 through 0.4.14, 0.5.x before 0.5.38, 0.6.x before 0.6.39, 0.7.x before 0.7.62, and 0.8.x before 0.8.14 allows remote attackers to cause a denial of service (NULL pointer dereference and worker process crash) via a long URI.