Vulnerability details

### Summary `minimatch` is vulnerable to Regular Expression Denial of Service (ReDoS) when a glob pattern contains many consecutive `*` wildcards followed by a literal character that doesn't appear in the test string. Each `*` compiles to a separate `[^/]*?` regex group, and when the match fails, V8's regex engine backtracks exponentially across all possible splits. The time complexity is O(4^N) where N is the number of `*` characters. With N=15, a single `minimatch()` call takes ~2 seconds. With N=34, it hangs effectively forever. ### Details _Give all details on the vulnerability. Pointing to the incriminated source code is very helpful for the maintainer._ ### PoC When minimatch compiles a glob pattern, each `*` becomes `[^/]*?` in the generated regex. For a pattern like `***************X***`: ``` /^(?!\.)[^/]*?[^/]*?[^/]*?[^/]*?[^/]*?[^/]*?[^/]*?[^/]*?[^/]*?[^/]*?[^/]*?[^/]*?[^/]*?[^/]*?[^/]*?X[^/]*?[^/]*?[^/]*?$/ ``` When the test string doesn't contain `X`, the regex engine must try every possible way to distribute the characters across all the `[^/]*?` groups before concluding no match exists. With N groups and M characters, this is O(C(N+M, N)) — exponential. ### Impact Any application that passes user-controlled strings to `minimatch()` as the pattern argument is vulnerable to DoS. This includes: - File search/filter UIs that accept glob patterns - `.gitignore`-style filtering with user-defined rules - Build tools that accept glob configuration - Any API that exposes glob matching to untrusted input ---- Thanks to @ljharb for back-porting the fix to legacy versions of minimatch.