---
id: CVE-2026-72588
title: >-
  A user enumeration vulnerability in bluewave-labs/Checkmate through 2.1.0
  allows an unauthenticated remote attacker to determine whether a given email
  address is registered
summary: >-
  A user enumeration vulnerability in bluewave-labs/Checkmate through 2.1.0
  allows an unauthenticated remote attacker to determine whether a given email
  address is registered. The POST /api/v1/auth/recovery/request endpoint returns
  HTTP 20…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-204
published: '2026-08-10'
updated: '2026-08-28'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-72588'
references:
  - url: 'https://github.com/bluewave-labs/Checkmate'
    label: 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
tags:
  - nvd
epss: 0.0042
epssPercentile: 0.33657
ingestedAt: '2026-08-29T17:39:55.834Z'
---

## Overview

A user enumeration vulnerability in bluewave-labs/Checkmate through 2.1.0 allows an unauthenticated remote attacker to determine whether a given email address is registered. The POST /api/v1/auth/recovery/request endpoint returns HTTP 200 for registered email addresses and a different status code for unregistered ones, enabling attackers to enumerate valid user accounts.

## Remediation

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