Cyber Resilience

CVE-2026-84197

Crypto Weakness

Published
08 September 2026
Modified
09 September 2026
CVSS Score v4 9.2
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0020 11th percentile
Risk Priority 43 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-84197 is a critical-severity Improper Certificate Validation (CWE-295) vulnerability in Eclipse Ditto (inferred from references). Its CVSS base score is 9.2 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Adversary-in-the-Middle (T1557); ranked at the 11th 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 IA-3 (Device Identification and Authentication) and SC-11 (Trusted Path) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

In Eclipse Ditto's Node.js JavaScript client, all released versions of @eclipse-ditto/ditto-javascript-client-node from 2.0.0 to 3.9.0 and of its predecessor package @eclipse-ditto/ditto-javascript-client-node_1.0 from 1.0.0 to 2.1.0, the WebSocket transport hard-codes rejectUnauthorized: false when creating the underlying ws WebSocket. Certificate chain and…

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hostname validation are therefore disabled for every wss:// connection, and no builder option, constructor argument or environment variable lets an application turn validation back on. An attacker in a position to intercept the connection can present an arbitrary certificate, complete the TLS handshake, read the credentials that the configured authentication provider sends in the Authorization header of the WebSocket upgrade request, and read, alter or inject Ditto Protocol messages for the lifetime of the connection. The Java client, the browser/DOM JavaScript client and the HTTP transport of the Node.js client are not affected.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

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.
T1040 Network Sniffing Credential Access
Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network.
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.
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.
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.
T1557.004 Evil Twin Credential Access
Adversaries may host seemingly genuine Wi-Fi access points to deceive users into connecting to malicious networks as a way of supporting follow-on behaviors such as [Network Sniffing](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2009-3555Shared CWE-295, CWE-300
CVE-2024-38324Shared CWE-295, CWE-297
CVE-2023-5909Shared CWE-295, CWE-297
CVE-2025-68161Shared CWE-295, CWE-297
CVE-2026-34477Shared CWE-295, CWE-297
CVE-2026-22747Shared CWE-295, CWE-297
CVE-2026-12064Shared CWE-295, CWE-297
CVE-2023-34143Shared CWE-295, CWE-297
CVE-2026-43869Shared CWE-295, CWE-297
CVE-2026-49457Shared CWE-295, CWE-297

Affected Assets

Eclipse
Ditto
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 17 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V17.2.8
  • V12.3.5

Mitigating Controls (NIST 800-53 r5) AI

IA-3 mandates device identification and authentication prior to establishing communications, addressing the non-endpoint actor risk.

SC-23 enforces session authenticity protections that verify both endpoints and prevent channel manipulation by outsiders.

SC-11 provides an isolated trusted path that cryptographically or physically assures the identities of the two endpoints.

PKI certificate issuance and acquisition under an approved policy establishes the trusted roots and processes needed for correct validation.

Requiring confidentiality and integrity of transmitted data necessitates correct TLS certificate validation with host-name checking.

AC-17 Remote Access partial match

AC-17 requires documented usage restrictions and secure configuration for remote access channels, reducing exposure to non-endpoint actors.

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.

ID.RA-09 partial match
prevents

Assessing authenticity/integrity of acquired software often relies on code-signing certificate validation.

PR.AA-03 partial match
prevents

Certificate-based authentication of users/services/hardware directly depends on correct validation.

PR.AA-04 partial match
prevents

Identity assertions conveyed via certificates require validation to be verified.

PR.DS-02 partial match
prevents

Proper certificate validation is a core mechanism for protecting data-in-transit confidentiality and integrity.

PR.IR-01 partial match
prevents

Reduces unauthorized network access that could exploit an unprotected channel.

PR.PS-06 partial match
prevents

Secure development practices explicitly include implementing correct certificate validation logic.

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.

prevents

Information transfer policies address secure exchange but are high-level and not technical.

degrades

Network security controls include certificate validation and host-name verification to prevent man-in-the-middle attacks.

degrades

Security of network services requires proper TLS configuration and certificate validation for service endpoints.

mitigates

Network segregation reduces exposure but does not verify endpoint identity or channel integrity.

prevents

Requiring issuance and validation of public-key certificates under an approved policy reduces the chance that certificates with improper validation will be trusted.

prevents

Application security requirements include secure communication and certificate validation for external services.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (6 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-295, CWE-300
  • V-248531 OL 8, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. prevents CWE-295
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
Oracle Linux 9 (1 rule)
  • V-271462 OL 9 must not have a File Transfer Protocol (FTP) server package installed. prevents CWE-300
RHEL 7 (2 rules)
  • V-204447 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
  • V-204448 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
RHEL 8 (2 rules)
  • V-230264 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295

References