CWE-807Weakness · CWE-807

CVE-2025-13926

CRITICAL · 9.8 CVSS v3.1 Published 2026-04-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
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
An attacker could use data obtained by sniffing the network traffic to forge packets in order to make arbitrary requests to Contemporary Controls BASC 20T.

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 Contemporary Controls BASC 20T transmits network data without adequate protection, allowing an attacker who sniffs traffic to obtain session credentials or command structures. The attacker can then forge or replay these packets to make arbitrary requests to the device, likely bypassing authentication due to the lack of encryption or anti-replay safeguards on the communication channel.

MitigationIsolate the BASC 20T on a dedicated, firewalled network segment; if remote access is required, tunnel communications through a VPN with encrypted tunnels to prevent sniffing and packet forgery.

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/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 BASC 20T device on your network
    Use network scanning tools (such as nmap, Angry IP Scanner, or your network management system) to discover devices. Look for devices with hostname, MAC OUI matching Contemporary Controls, or port signatures indicating BAS protocols. Confirm the exact model number through device documentation or management interface.
    Affected if The device on your network is confirmed to be a Contemporary Controls BASC 20T controller.
  2. Capture and inspect outbound network traffic
    Use a packet capture tool (such as Wireshark or tcpdump) on a span port or tap positioned to observe traffic to and from the BASC 20T. Filter for traffic involving the device IP and examine the protocol layers. Look for cleartext protocols, unencrypted application-layer data, or recognizable BAS protocol patterns.
    Affected if Network traffic to/from the device is transmitted in cleartext without TLS or equivalent encryption layer.
  3. Check for encryption on BAS protocol communication
    Examine captured packets for the presence of TLS/SSL handshake (ClientHello, ServerHello) or other encryption indicators. For BAS protocols (BACnet, Modbus, or proprietary), verify whether encryption options are available and enabled in the device configuration.
    Affected if The device uses an unencrypted BAS protocol without TLS wrapping or equivalent transport encryption.
  4. Inspect for sensitive data exposure in traffic
    Within captured packets, search for visible usernames, passwords, device credentials, session tokens, or command structures that could be extracted and reused to forge requests. Use Wireshark follow-stream or strings to examine payload content.
    Affected if Cleartext credentials, session identifiers, or predictable command structures are observable in captured network traffic.
  5. Verify network isolation of the device
    Review network segmentation policies, VLAN assignments, and firewall rules to determine whether the BASC 20T is isolated from untrusted networks or the internet. Check if the device is directly accessible from management or guest networks.
    Affected if The BASC 20T lacks network isolation and is reachable from untrusted network segments, combined with unencrypted communications.

Your environment is affected if the BASC 20T transmits network traffic in cleartext or uses unencrypted protocols, allowing an attacker with packet capture ability to extract sufficient information for crafting forged requests.

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

Isolate the BASC 20T on a dedicated, firewalled network segment; if remote access is required, tunnel communications through a VPN with encrypted tunnels to prevent sniffing and packet forgery.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA4.0 h
26.0 hours of engineering $4,580
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-13926 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2025-13926 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
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  • Version or environment caveats, and links to real fixes
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