dbcve.org
Code InjectionWeakness · CWE-94

CVE-2026-25817

HIGH · 8.8 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 →
94/100
Remediation priority · Urgent
Remotely reachable 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 have improper neutralization of special elements used in an OS command allowing remote code execution by attackers with low privilege access on the gateway, provided the attacker has credentials.

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

OS command injection vulnerability in HMS Networks Ewon Flexy and Cosy+ gateways allows authenticated attackers with low-privilege credentials to execute arbitrary OS commands due to improper neutralization of special elements in command input.

MitigationUpgrade firmware to version 15.0s4 (Flexy), 22.1s6 (Cosy+ 22.xx), or 23.0s3 (Cosy+ 23.xx) or later. Until patched, limit access to management interfaces and enforce strong credential policies.

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 the Ewon device model
    Access the device web interface or check the device label/serial number. The Flexy and Cosy+ are industrial VPN gateways. Navigate to the main status page or 'System > Information' to confirm the device type.
    Affected if The device is an Ewon Flexy or Cosy+ gateway.
  2. Check the installed firmware version
    In the web interface, go to 'System > Information' or 'Setup > System' and locate the firmware version field. Alternatively, use the Ewon firmware update tool or check via FTP/SFTP access to the device if enabled.
    Affected if The firmware version is below 15.0s4 for Flexy, below 22.1s6 for Cosy+ 22.xx, or below 23.0s3 for Cosy+ 23.xx.
  3. Verify the web-based command interface is accessible
    Check if the device's web management interface (port 80/443) is exposed and accessible on the network. Look for features labeled as 'Command', 'Terminal', 'Diagnostics', or 'System Command' within the web interface.
    Affected if The web management interface is accessible and the command execution feature is present and enabled.
  4. Confirm user accounts with low-privilege access exist
    In the web interface, navigate to 'Setup > Users' or 'Security > User Accounts' to review configured users. This vulnerability affects any authenticated user, including those with basic or restricted privilege levels.
    Affected if There is at least one user account configured with any privilege level on the device.

The device is affected if it is an Ewon Flexy or Cosy+ with firmware version below the patched releases AND the web management interface is accessible with user accounts configured.

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

Upgrade firmware to version 15.0s4 (Flexy), 22.1s6 (Cosy+ 22.xx), or 23.0s3 (Cosy+ 23.xx) or later. Until patched, limit access to management interfaces and enforce strong credential policies.

Recommended fix High confidence

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

  1. Identify the specific HMS Networks device model (Ewon Flexy or Cosy+) and current firmware version
  2. For Ewon Flexy: Download and install firmware version 15.0s4 or later from HMS Networks support
  3. For Cosy+ with firmware 22.xx: Download and install firmware version 22.1s6 or later
  4. For Cosy+ with firmware 23.xx: Download and install firmware version 23.0s3 or later
  5. Verify the firmware upgrade was successful by checking the version in the device web interface or management console
  6. Test that critical device functionality operates normally after the upgrade

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

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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Scan for this in your stack

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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-2026-25817 in production — separate from our analysis above.

No notes yet

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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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data