---
id: "CVE-2026-112366"
kind: "vulnerability"
aliases: ["CVE-2026-112366"]
title: "Picomatch: crafted extglob patterns freeze Node.js event loop"
severity: "high"
cvss: 8.7
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["node.js", "npm", "package", "picomatch", "self-hosted"]
not_affected_if: ["auth-required", "no-user-supplied-globs"]
published_at: "2026-10-19T16:17:07+00:00"
first_seen_at: "2026-10-23T21:57:18+00:00"
updated_at: "2026-10-23T22:37:30+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-112366", "first_seen_at": "2026-10-23T21:57:18+00:00"}]
---

# Picomatch: crafted extglob patterns freeze Node.js event loop

Picomatch through 4.0.7 mishandles repeated extglob patterns such as +(*) or +(*a), causing exponential regex backtracking on short strings. An attacker who can supply such a glob can block the Node.js event loop and deny service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

Run `npm ls picomatch` (and `pnpm why picomatch`) to find installed versions and whether any Node.js app passes user-supplied globs to picomatch.

## Fix

Upgrade picomatch to a release newer than 4.0.7; the fixed version is unknown from the sources, so check the picomatch changelog or npm.
If upgrading is not possible, reject or sanitize user-supplied glob patterns containing extglob syntax.

## Timeline

- 2026-10-23T21:57:18+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-112366

## From the sources

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_