Fix ReDoS vulnerability in StringUtils#underscore
#209
+16
−2
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## Summary Replace regex patterns with lookahead/lookbehind assertions to prevent catastrophic backtracking on Ruby 3.1 and earlier. This issue only affects Ruby 3.1 and earlier. Since it does not occur on Ruby 3.2+, it is not an issue in the current stable release (0.4.0), which does not include modelcontextprotocol#206. ## Regression Testing Ensure the regex patterns complete within 1 second for a 50,000-character input that would otherwise trigger superlinear backtracking.
atesgoral
approved these changes
Jan 9, 2026
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Motivation and Context
Replace regex patterns with lookahead/lookbehind assertions to prevent catastrophic backtracking on Ruby 3.1 and earlier.
This issue only affects Ruby 3.1 and earlier. Since it does not occur on Ruby 3.2+, it is not an issue in the current stable release (0.4.0), which does not include #206.
How Has This Been Tested?
Ensure the regex patterns complete within 1 second for a 50,000-character input that would otherwise trigger superlinear backtracking.
Breaking Changes
None.
Types of changes
Checklist