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Missing AuthenticationWeakness · CWE-306

CVE-2026-2491

MEDIUM · 6.3 CVSS v3.0 Published 2026-03-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
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
Socomec DIRIS A-40 HTTP API Authentication Bypass Vulnerability. This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of Socomec DIRIS A-40 power monitoring devices. Authentication is not required to exploit this vulnerability. The specific flaw exists within the web API implementation, which listens on TCP port 80 by default. The issue results from the lack of authentication prior to allowing access to functionality. An attacker can leverage this vulnerability to bypass authentication on the system. Was ZDI-CAN-23993.

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 · moderate confidence

The Socomec DIRIS A-40 power monitoring device has an authentication bypass vulnerability in its HTTP API listening on TCP port 80. Attackers on the adjacent network can access API functionalities without any authentication credentials, allowing them to potentially control or extract data from the power monitoring system.

MitigationRestrict network access to the DIRIS A-40 device's HTTP API (port 80) using network segmentation and firewall rules to limit exposure to only trusted network segments, since vendor patches may not be immediately available.

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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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 device model
    Check the device label, web interface banner, or system information page for the exact model number DIRIS A-40. Some devices display model info on the login page or in the footer.
    Affected if The device is a Socomec DIRIS A-40 power monitoring unit.
  2. Confirm HTTP service is running on port 80
    Run 'netstat -an | grep :80' or 'nmap -p 80 <device_ip>' from a client workstation to verify the HTTP API is listening on TCP port 80.
    Affected if Port 80 is open and accepting TCP connections on the DIRIS A-40 device.
  3. Test API access without credentials
    Use curl or a browser to request http://<device_ip>/api/ or http://<device_ip>/rest/ (common API endpoints). Observe whether the system returns data or a login prompt without providing any username or password.
    Affected if The API returns operational data, configuration, or device status without requiring any authentication token or login.
  4. Check network accessibility from untrusted segments
    Verify whether the device IP is reachable from network segments outside the trusted management VLAN. Use 'ping <device_ip>' or port scan from an untrusted host to confirm adjacent network access is possible.
    Affected if The DIRIS A-40 device is reachable from network segments beyond the intended trusted network.
  5. Review firewall or network segmentation rules
    Inspect the network firewall, VLAN configuration, or ACLs protecting the device. Check if port 80 traffic is allowed from any source or from untrusted zones.
    Affected if No firewall rule exists to restrict port 80 access to trusted IP addresses only, or the device is in an unsegmented network zone.

A user is affected if they have a DIRIS A-40 device with its HTTP API on port 80 exposed to any untrusted network segment and the API returns data without prompting for authentication.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Restrict network access to the DIRIS A-40 device's HTTP API (port 80) using network segmentation and firewall rules to limit exposure to only trusted network segments, since vendor patches may not be immediately available.

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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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-2026-2491 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
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