---
id: CVE-2026-107586
title: >-
  Uncontrolled eviction in the browser session table of the REST API in
  Progressive Robot hMailServer 6.2.28 through 6.3.5 allows a remote
  authenticated user to end other users' sessions
summary: >-
  Uncontrolled eviction in the browser session table of the REST API in
  Progressive Robot hMailServer 6.2.28 through 6.3.5 allows a remote
  authenticated user to end other users' sessions. The table of browser
  sessions, shared by every acco…
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-770
vendor: Progressive Robot Ltd
product: hMailServer
affected:
  - hMailServer >= 6.2.28 < 6.3.6
published: '2026-10-08'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T21:02:43.860'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-107586'
references:
  - url: 'https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6'
    label: cve@gitlab.com
  - url: 'https://gitlab.com/hmailserver/hmailserver/-/work_items/62'
    label: cve@gitlab.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-08T15:49:37.991Z'
---

## Overview

Uncontrolled eviction in the browser session table of the REST API in Progressive Robot hMailServer 6.2.28 through 6.3.5 allows a remote authenticated user to end other users' sessions. The table of browser sessions, shared by every account, the server administrator and support sessions, dropped its least recently used session whenever it was full, whoever it belonged to, and placed no limit on how many sessions one account could hold. A user who repeatedly signs in with their own mailbox password can therefore keep the table full and sign out every webmail and administration session that is idle for more than a short time, for as long as they continue.

## Remediation

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