---
id: CVE-2026-61503
title: Rejetto HFS < 3.2.1 Username Enumeration via Login Response Differences
summary: >-
  Rejetto HFS 3.0.0 through 3.2.0 returns observably different responses from
  its login endpoint depending on whether the submitted username exists. A
  remote unauthenticated attacker can use this to confirm valid account names,
  including t…
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'
cvssSource: cna
cwe:
  - CWE-204
vendor: rejetto
product: hfs
affected:
  - hfs >= 3.0.0 < 3.2.1
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-07-15T19:07:07.143075Z'
published: '2026-07-13'
updated: '2026-10-01'
sourceUpdated: '2026-10-01T15:20:11.068Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-61503'
references:
  - url: 'https://github.com/rejetto/hfs/releases/tag/v3.2.1'
    label: hfs v3.2.1 Release Notes
  - url: >-
      https://www.vulncheck.com/advisories/rejetto-hfs-username-enumeration-via-login-response-differences
tags:
  - cve.org
epss: 0.00436
epssPercentile: 0.35603
ingestedAt: '2026-10-01T15:48:17.860Z'
---

## Overview

Rejetto HFS 3.0.0 through 3.2.0 returns observably different responses from its login endpoint depending on whether the submitted username exists. A remote unauthenticated attacker can use this to confirm valid account names, including the default admin account, facilitating password-guessing and session-forgery attacks.

## Affected

- `hfs >= 3.0.0 < 3.2.1`

## Remediation

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