Picomatch through 4.0.7 ReDoS via single-branch repeated extglob patterns

Summary

Picomatch through 4.0.7 contains a regular expression denial of service vulnerability that allows attackers to block the event loop by supplying single-branch repeated extglob patterns. Attackers can provide globs like +(*) or +(*a), which analyzeRepeatedExtglob in lib/parse.js skips, causing exponential backtracking against short crafted strings and denying service to Node.js applications.

Evidence

Reported to the maintainer with a proof of concept that reproduced against the affected release.

Remediation

No fixed release is listed in the advisory. Check the references for upstream status.

References

• VulnCheck advisoryhttps://www.vulncheck.com/advisories/picomatch-through-4.0.7-redos-via-single-branch-repeated-extglob-patterns
• Fix pull requesthttps://github.com/micromatch/picomatch/pull/194
• Vulnerable codehttps://github.com/micromatch/picomatch/blob/4.0.7/lib/parse.js#L287-L307
• CVE recordhttps://www.cve.org/CVERecord?id=CVE-2026-112366