CVE-2026-4926

Severity CVSS v4.0:

Pending analysis

Type:

CWE-400 Uncontrolled Resource Consumption ('Resource Exhaustion')

Publication date:

26/03/2026

Last modified:

16/04/2026

Description

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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.50 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x

7.50

Severity 3.x

HIGH

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:pillarjs:path-to-regexp::::::node.js::*	8.0.0 (including)	8.4.0 (excluding)

To consult the complete list of CPE names with products and versions, see this page

References to Advisories, Solutions, and Tools

https://cna.openjsf.org/security-advisories.html