Cyber Resilience

CVE-2026-4374

High

Published: 01 April 2026

Published
01 April 2026
Modified
21 April 2026
KEV Added
Patch
CVSS Score v4 8.8 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:H/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 0.0024 14.2th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-4374 is a high-severity Improper Restriction of XML External Entity Reference (CWE-611) vulnerability in Rti Connext Professional. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 14.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Deeper analysis

CVE-2026-4374 is an Improper Restriction of XML External Entity Reference vulnerability (CWE-611) in RTI Connext Professional, affecting the Routing Service, Observability Collector, Recording Service, Queueing Service, and Cloud Discovery Service. The issue enables Serialized Data External Linking and Data Serialization flaws. It was published on 2026-04-01 and carries a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H).

An unauthenticated remote attacker can exploit this vulnerability over the network with low attack complexity and without requiring user interaction. Successful exploitation can result in high impacts to confidentiality and availability, allowing unauthorized access to sensitive data and disruption of service.

Mitigation guidance and patches are detailed in the RTI vulnerability advisory at https://www.rti.com/vulnerabilities/#cve-2026-4374.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Improper Restriction of XML External Entity Reference vulnerability in RTI Connext Professional (Routing Service,Observability Collector,Recording Service,Queueing Service,Cloud Discovery Service) allows Serialized Data External Linking, Data Serializat...

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
Why these techniques?

Remote unauthenticated XXE in exposed services directly enables T1190 for initial exploitation and T1005 for local file/data access via external entity processing.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-54254Shared CWE-611
CVE-2025-68493Shared CWE-611
CVE-2023-47160Shared CWE-611
CVE-2024-49781Shared CWE-611
CVE-2025-23195Shared CWE-611
CVE-2025-36589Shared CWE-611
CVE-2024-8010Shared CWE-611
CVE-2024-54171Shared CWE-611
CVE-2026-29924Shared CWE-611
CVE-2024-56324Shared CWE-611

Affected Assets

rti
connext professional
5.3.0 — 5.3.1.45 · 6.0.0 — 6.0.1.40 · 6.1.0 — 6.1.2.27

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly mandates identification, reporting, and timely remediation of the XXE flaw in RTI Connext services via patching as detailed in the RTI advisory.

prevent

Requires validation of XML inputs to block improper external entity references that enable unauthorized data access and service disruption.

prevent

Enforces secure configuration settings for XML parsers in affected RTI services to disable external entity processing and mitigate serialization flaws.

References