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Uncontrolled Resource ConsumptionWeakness · CWE-400

CVE-2026-25819

HIGH · 7.5 CVSS v3.1 Published 2026-03-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
HMS Networks Ewon Flexy with firmware before 15.0s4, Cosy+ with firmware 22.xx before 22.1s6, and Cosy+ with firmware 23.xx before 23.0s3 allows unauthenticated attackers to cause a Denial of Service by using a specially crafted HTTP request that leads to a reboot of the device, provided they have access to the device's GUI.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

HMS Networks Ewon Flexy and Cosy+ devices contain a denial-of-service vulnerability where unauthenticated attackers with access to the device's GUI can send specially crafted HTTP requests that cause the device to reboot, resulting in service disruption. The vulnerability is exploitable without authentication once GUI access is available.

MitigationUpdate firmware to version 15.0s4 (Flexy), 22.1s6 (Cosy+ 22.xx), or 23.0s3 (Cosy+ 23.xx) per vendor guidance. Restrict GUI access to trusted networks or users to reduce attack surface.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify device model
    Access the device web interface or use the device's diagnostic page to determine if it is an Ewon Flexy or Cosy+ device. Check the device label or firmware information page.
    Affected if Device is an Ewon Flexy or Cosy+ unit
  2. Check firmware version
    Log into the device GUI or check system information page to find the installed firmware version number. Compare against 15.0s4 for Flexy, 22.1s6 for Cosy+ 22.xx, or 23.0s3 for Cosy+ 23.xx.
    Affected if Firmware version is below 15.0s4 on Flexy, below 22.1s6 on Cosy+ 22.xx, or below 23.0s3 on Cosy+ 23.xx
  3. Verify GUI is enabled
    Navigate to the device configuration settings and check if the web-based GUI or HTTP interface is enabled. Look for settings under Network > Services or similar.
    Affected if HTTP/GUI service is enabled on the device
  4. Assess GUI network accessibility
    Check the network bind settings for the GUI service. Determine if it is bound to all interfaces (0.0.0.0) or only localhost. Review firewall or access control rules that may permit external HTTP access to the device.
    Affected if GUI is accessible over the network rather than localhost only, and is reachable from untrusted networks

A device is affected if it is an Ewon Flexy or Cosy+ with GUI enabled, running firmware below the fixed versions, and the GUI is network-accessible to untrusted attackers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update firmware to version 15.0s4 (Flexy), 22.1s6 (Cosy+ 22.xx), or 23.0s3 (Cosy+ 23.xx) per vendor guidance. Restrict GUI access to trusted networks or users to reduce attack surface.

Recommended fix High confidence

Ewon Flexy: firmware 15.0s4; Cosy+ 22.xx: firmware 22.1s6; Cosy+ 23.xx: firmware 23.0s3

  1. 1. Identify the HMS Networks device model (Ewon Flexy or Cosy+) and current firmware version by accessing the device's web GUI
  2. 2. For Ewon Flexy devices: Upgrade firmware to version 15.0s4 or later
  3. 3. For Cosy+ devices running 22.xx firmware branch: Upgrade firmware to version 22.1s6 or later
  4. 4. For Cosy+ devices running 23.xx firmware branch: Upgrade firmware to version 23.0s3 or later
  5. 5. Download the appropriate firmware update from the official HMS Networks support website (www.hms-networks.com)
  6. 6. Apply the firmware update following the vendor's documented upgrade procedure for the specific device
  7. 7. After reboot, verify the device is running the patched firmware version and accessible via GUI

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,840
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-25819 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data