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CVE-2026-4926

CVE-2026-4926 · path-to-regexp vulnerable to Denial of Service via sequential optional groups

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 7.5 · High · EPSS 0.8% · Fix available

Published
Updated

Stack: system · node

Affected products and versions

  • path-to-regexp

    Versions
    • ≥ 8.0.0, < 8.4.0: Affected (semver)
    • 8.4.0: Not affected (semver)

    Update to 8.4.0

  • node-path-to-regexp Debian:12

    Versions
    • 6.2.1-1
    • 6.3.0-1
    • 8.3.0-1
    • 8.4.0-1
    • 8.4.1-1
    • 8.4.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-path-to-regexp Debian:13

    Versions
    • 6.3.0-1
    • 8.3.0-1
    • 8.4.0-1
    • 8.4.1-1
    • 8.4.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-path-to-regexp Debian:14

    Versions
    • 6.3.0-1
    • 8.3.0-1
    Affected ranges
    • ECOSYSTEM: < 8.4.0-1

    Update to 8.4.0-1

  • path-to-regexp npm

    Affected ranges
    • SEMVER: ≥ 8.0.0, < 8.4.0

    Update to 8.4.0

Original sources

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