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levenshtein() and levenshtein_less_equal() let the caller specify the insertion, deletion, and substitution costs, and fuzzystrmatch's corresponding SQL functions accept any 32-bit integer for each. Since the distances are calculated with 32-bit arithmetic, large costs can cause overflows, thereby producing nonsensical results. Certain inputs to levenshtein_less_equal() can even cause out-of-bounds writes. To fix, use 64-bit arithmetic instead, and error whenever the final result won't fit in the returned 32-bit integer. We may want to teach these functions to reject negative costs, too, but that didn't seem appropriate for a security fix, and therefore it is left as a future exercise. Reported-by: Ben Morris in collaboration with Claude and Anthropic Research Author: Nathan Bossart <nathandbossart@gmail.com> Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com> Security: CVE-2026-15742 Backpatch-through: 14