Cyber Resilience

CVE-2026-40434

Anviz Crosschex Standard

Published
17 April 2026
Modified
04 May 2026
Patch / advisory
View advisory
CVSS Score v3.1 8.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
EPSS Score 0.0023 14th percentile
Risk Priority 58 floored blend · peak EPSS

Summary

CVE-2026-40434 is a high-severity Improper Verification of Source of a Communication Channel (CWE-940) vulnerability in Anviz Crosschex Standard. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique ARP Cache Poisoning (T1557.002); ranked at the 14th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-17 (Remote Access) and IA-3 (Device Identification and Authentication) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-40434 is a vulnerability in Anviz CrossChex Standard, where the client/server channel lacks source verification, as defined by CWE-940 (Improper Verification of Source of a Communication Channel). This flaw enables TCP packet injection by an attacker on the same network, allowing them to alter or disrupt application traffic. The vulnerability received a CVSS v3.1 base score of 8.1 (AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H), highlighting high impacts on integrity and availability with no confidentiality impact.

An adjacent network attacker can exploit this issue with low complexity, no required privileges, and no user interaction. Exploitation involves injecting malicious TCP packets into the client/server communication, enabling the attacker to modify traffic content or cause disruptions such as denial of service.

Advisories including CISA ICSA-26-106-03 (https://www.cisa.gov/news-events/ics-advisories/icsa-26-106-03) and the associated CSAF file (https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-106-03.json) provide further details. Anviz support is available at https://www.anviz.com/contact-us.html.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability Data

Anviz CrossChex Standard lacks source verification in the client/server channel, enabling TCP packet injection by an attacker on the same network to alter or disrupt application traffic.

CWE(s)
CWE-940

Related Threats

MITRE ATT&CK Enterprise Techniques

T1557.002 ARP Cache Poisoning Credential Access
Adversaries may poison Address Resolution Protocol (ARP) caches to position themselves between the communication of two or more networked devices.
attack.mitre.org →
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
attack.mitre.org →
T1557.001 Name Resolution Poisoning and SMB Relay Credential Access
By responding to LLMNR/NBT-NS/mDNS network traffic, adversaries may spoof an authoritative source for name resolution to force communication with an adversary controlled system.
attack.mitre.org →
T1557.003 DHCP Spoofing Credential Access
Adversaries may redirect network traffic to adversary-owned systems by spoofing Dynamic Host Configuration Protocol (DHCP) traffic and acting as a malicious DHCP server on the victim network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-32650Same product: Anviz Crosschex Standard
CVE-2025-40820Shared CWE-940
CVE-2025-23019Shared CWE-940
CVE-2023-3663Shared CWE-940
CVE-2025-13086Shared CWE-940
CVE-2025-42978Shared CWE-940
CVE-2024-40503Shared CWE-940
CVE-2026-48745Shared CWE-940
CVE-2019-25613Shared CWE-940
CVE-2025-62439Shared CWE-940

Affected Assets

anviz
crosschex standard
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V3.5.3
  • V10.6.2
  • V15.2.4

Mitigating Controls (NIST 800-53 r5) AI

IA-3 Device Identification and Authentication good match

IA-3 requires unique identification and authentication of devices before any communication channel is established, directly stopping acceptance of unverified origins.

AC-17 Remote Access good match

AC-17 mandates documented restrictions and authentication requirements for remote access, blocking channels whose origins are not properly verified.

SC-23 Session Authenticity partial match

SC-23 protects session authenticity, ensuring the source of an established communication channel is verified and cannot be spoofed.

SC-7 Boundary Protection partial match

SC-7 enforces monitoring and control at external and key internal interfaces, preventing channels from unverified sources via boundary rules.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 full match
prevents

Authentication of users/services/hardware directly enforces source verification for communication channels.

PR.AA-04 mostly match
prevents

Verifying identity assertions prevents spoofed channel origins but does not cover all channel-establishment scenarios.

PR.IR-01 partial match
prevents

Network protections reduce unauthorized channel usage but do not specifically require origin verification at channel setup.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.5 Secure authentication mostly match
prevents

Secure authentication mechanisms verify the identity and origin of communication channel initiators.

A.8.20 Networks security partial match
degrades

Network security controls enforce source verification and channel authentication for incoming communications.

A.8.21 Security of network services partial match
degrades

Security of network services includes validating the origin of service requests and connections.

A.8.22 Segregation of networks partial match
mitigates

Network segregation limits exposure but does not directly verify source of individual channels.

A.8.24 Use of cryptography partial match
prevents

Cryptography can support channel authentication but does not inherently verify source without proper implementation.

A.8.26 Application security requirements partial match
prevents

Application security requirements may specify origin checks but do not mandate them.

References