---
id: GHSA-6h2x-m376-mqjq
title: 'joi: Quadratic regular-expression backtracking in `Joi.string().isoDate()`'
summary: 'joi: Quadratic regular-expression backtracking in `Joi.string().isoDate()`'
severity: high
cvss: 7.5
cwe:
  - CWE-1333
vendor: joi
product: joi
ecosystem: npm
affected:
  - 'joi >= 17.2.0, < 17.13.7'
  - 'joi >= 18.0.0, < 18.2.6'
patched:
  - joi 17.13.7
  - joi 18.2.6
published: '2026-09-29'
updated: '2026-09-29'
sourceUpdated: '2026-09-29T18:07:43Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-6h2x-m376-mqjq'
references:
  - url: 'https://github.com/hapijs/joi/security/advisories/GHSA-6h2x-m376-mqjq'
  - url: 'https://github.com/hapijs/joi/pull/3143'
  - url: 'https://github.com/hapijs/joi/pull/3145'
  - url: >-
      https://github.com/hapijs/joi/commit/115e7b58d5eaaecc5e9b7093d41899ad6fb053ec
  - url: >-
      https://github.com/hapijs/joi/commit/e70df424c367f2976db63b089504413744a21245
  - url: 'https://github.com/advisories/GHSA-6h2x-m376-mqjq'
tags:
  - ghsa
  - npm
ingestedAt: '2026-09-29T18:42:35.832Z'
---

## Overview

### Impact
Any application that validates a user-supplied string with `Joi.string().isoDate()` can be stalled by a single request. One of the regular expressions the rule runs over the input was unanchored, so a valid ISO date followed by a long run of fractional-second digits made the regex engine restart its search from every position in the string, costing time proportional to the square of the input length. 64 KB of digits costs about 1.4 s and 256 KB about 22 s.

### Patches
Upgrade to version 17.13.7 or 18.2.6 depending on your current major version.

### Workarounds
None except capping the length of the string before it reaches joi.

## Affected packages

- `joi >= 17.2.0, < 17.13.7`
- `joi >= 18.0.0, < 18.2.6`

## Remediation

Upgrade to a patched release:

- `joi 17.13.7`
- `joi 18.2.6`