4.3
MEDIUM CVSS 3.1
CVE-2026-107586
Allocation of Resources Without Limits or Throttling in hMailServer
Description

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.

INFO

Published Date :

Oct. 8, 2026, 3:17 p.m.

Last Modified :

Oct. 8, 2026, 9:02 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-107586 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM ceab7361-8a18-47b1-92ba-4d7d25f6715a
CVSS 3.1 MEDIUM [email protected]
Solution
Address uncontrolled eviction in browser session table to prevent denial of service.
  • Update the application to patch the session management vulnerability.
  • Implement session limits per account.
  • Review and secure session handling logic.
  • Monitor session activity for abuse.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-107586.

URL Resource
https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6
https://gitlab.com/hmailserver/hmailserver/-/work_items/62
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-107586 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-107586 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-107586 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 08, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-107586', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-08T19:12:40.221197Z'}
  • New CVE Received by [email protected]

    Oct. 08, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
    Added CWE CWE-770
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/107xxx/CVE-2026-107586.json">CVE-2026-107586</a>
    Added Reference https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6
    Added Reference https://gitlab.com/hmailserver/hmailserver/-/work_items/62
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.