SECURITY UPDATE: heap buffer overflow in ngx_http_rewrite_module with
overlapping captures
debian/patches/CVE-2026-9256.patch: fix heap buffer overflow in
ngx_http_script_regex_start_code() when a rewrite replacement string
with no variables has overlapping captures, by moving the per-capture
length accumulation and ngx_escape_uri() call inside a single loop
over the actual captures buffer.