---
id: "CVE-2026-115887"
kind: "vulnerability"
aliases: ["CVE-2026-115887"]
title: "GraphQL Scalars: crafted phone number input stalls Node.js server via regex"
severity: "high"
cvss: 7.5
epss: 0.00742
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["graphql", "graphql-scalars", "node.js", "package", "self-hosted"]
not_affected_if: ["not-using-phonenumber-scalar", "version-2.0.1-or-later"]
published_at: "2026-10-23T22:16:58+00:00"
first_seen_at: "2026-10-23T23:44:51+00:00"
updated_at: "2026-10-25T12:38:49+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-115887", "first_seen_at": "2026-10-23T23:44:51+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-115887", "first_seen_at": "2026-10-25T12:38:49+00:00"}]
---

# GraphQL Scalars: crafted phone number input stalls Node.js server via regex

The GraphQLPhoneNumber scalar in the graphql-scalars library uses a regular expression with nested digit quantifiers that backtracks exponentially on certain input. A small unauthenticated GraphQL request can block the Node.js event loop and stall the server process.

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

## How to check

- Run `npm ls graphql-scalars` (or `yarn why graphql-scalars`) in the project and check the installed version.
- Check whether the schema uses `GraphQLPhoneNumber` from graphql-scalars.

## Fix

- Upgrade graphql-scalars to `2.0.1` or later.

## Timeline

- 2026-10-23T23:44:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-115887
- 2026-10-25T12:38:49+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-115887

## From the sources

GraphQL Scalars is a library of custom GraphQL scalars for creating precise type-safe GraphQL schemas. From 1.24.1 until 2.0.1, GraphQLPhoneNumber in src/scalars/PhoneNumber.ts uses ambiguous nested digit quantifiers that backtrack exponentially when a PhoneNumber value contains a run of digits followed by a character that makes the match fail. GraphQL evaluates parseLiteral during document validation and parseValue during variable coercion before resolver authentication or authorization, so a small unauthenticated request can block the Node.js event loop and stall the server process. serialize is also affected when unvalidated stored values are returned through the scalar. This issue is fixed in version 2.0.1.

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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_