cvedb.io
CVE-2026-4926
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2026-03-26T19:17:08.387 · Last modified 2026-06-30T03:20:44.527

Summary

Impact: A bad regular expression is generated any time you have multiple sequential optional groups (curly brace syntax), such as `{a}{b}{c}:z`. The generated regex grows exponentially with the number of groups, causing denial of service. Patches: Fixed in version 8.4.0. Workarounds: Limit the number of sequential optional groups in route patterns. Avoid passing user-controlled input as route patterns.

Affected products

pillarjs — path-to-regexp

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.