---
id: CVE-2026-123487
title: Parse Server 9.0.0 before 9.10.7-alpha.1 ReDoS via Email Validation Regex
summary: >-
  Parse Server before 8.6.115 and 9.0.0 before 9.10.7-alpha.1 validates user
  email address format with a regular expression whose run time grows
  quadratically with input length and that is applied without a length limit. An
  unauthenticated…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-1333
vendor: parse-community
product: parse-server
affected:
  - parse-server >= 9.0.0 < 9.10.7-alpha.1
  - parse-server < 8.6.115
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-11-06T17:11:55.570614Z'
published: '2026-11-06'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T17:14:55.801Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-123487'
references:
  - url: >-
      https://github.com/parse-community/parse-server/security/advisories/GHSA-9492-427f-466x
    label: GitHub Security Advisory (GHSA-9492-427f-466x)
  - url: >-
      https://www.vulncheck.com/advisories/parse-server-9.0.0-before-9.10.7-alpha.1-redos-via-email-validation-regex
    label: >-
      VulnCheck Advisory: Parse Server 9.0.0 before 9.10.7-alpha.1 ReDoS via
      Email Validation Regex
tags:
  - cve.org
ingestedAt: '2026-11-06T15:54:04.093Z'
epss: 0.00383
epssPercentile: 0.32555
---

## Overview

Parse Server before 8.6.115 and 9.0.0 before 9.10.7-alpha.1 validates user email address format with a regular expression whose run time grows quadratically with input length and that is applied without a length limit. An unauthenticated attacker who knows the application ID can send a sign-up request, or a logged-in user can update their own email, with a long crafted email address to block the Node.js event loop and deny service to all clients.

## Affected

- `parse-server >= 9.0.0 < 9.10.7-alpha.1`
- `parse-server < 8.6.115`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.