Cyber Resilience

CVE-2026-42403

DoS in Apache Neethi ≤ 3.2.2

Published
01 May 2026
Modified
01 May 2026
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0076 52th percentile
Risk Priority 59 floored blend · peak EPSS

Summary

CVE-2026-42403 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Apache Neethi. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Exhaustion Flood (T1499.001); ranked in the top 48% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-5 (Denial-of-service Protection) and SC-6 (Resource Availability) — 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-2026-42403 is a vulnerability in Apache Neethi, a Java library for processing WS-Policy documents. The issue stems from the library's failure to properly detect circular references in policy definitions. When a WS-Policy document includes circular references—such as Policy A referencing Policy B, which in turn references Policy A—the policy normalization process can enter an infinite loop or trigger excessive recursion. This results in a stack overflow or application hang, enabling a denial-of-service (DoS) condition. The vulnerability is rated with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) and is associated with CWE-400 (Uncontrolled Resource Consumption).

An unauthenticated attacker with network access can exploit this vulnerability by crafting and delivering a malicious WS-Policy document containing circular references to any application or service that processes WS-Policy via Apache Neethi. No user interaction or privileges are required, and exploitation requires low complexity. Successful exploitation leads to resource exhaustion, causing the targeted application to hang or crash due to stack overflow, thereby disrupting service availability without impacting confidentiality or integrity.

The Apache security advisory recommends upgrading to Apache Neethi version 3.2.2, which addresses the issue by improving circular reference detection during policy normalization. Additional details are available in the official Apache announcement and oss-security mailing list discussions.

EU & UK References

Vulnerability Data

Apache Neethi does not properly detect circular references in policy definitions. When a WS-Policy document contains circular policy references (where Policy A references Policy B which references Policy A), the policy normalization process can enter an infinite loop or cause…

more

excessive recursion, leading to a stack overflow or application hang. An attacker can craft malicious policy documents with circular references to cause a Denial of Service condition Users are recommended to upgrade to version 3.2.2, which fixes this issue.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499.001 OS Exhaustion Flood Impact
Adversaries may launch a denial of service (DoS) attack targeting an endpoint's operating system (OS).
T1498 Network Denial of Service Impact
Adversaries may perform Network Denial of Service (DoS) attacks to degrade or block the availability of targeted resources to users.
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.002 Service Exhaustion Flood Impact
Adversaries may target the different network services provided by systems to conduct a denial of service (DoS).
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-66144Same product: Apache Neethi
CVE-2026-66143Same product: Apache Neethi
CVE-2026-42402Same product: Apache Neethi
CVE-2026-66142Same product: Apache Neethi
CVE-2026-66299Same vendor: Apache
CVE-2025-48392Same vendor: Apache
CVE-2025-48795Same vendor: Apache
CVE-2026-32588Same vendor: Apache
CVE-2023-46104Same vendor: Apache
CVE-2026-59173Same vendor: Apache

Affected Assets

apache
neethi
≤ 3.2.2

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SC-5 directly limits the effects of resource-exhaustion events that constitute uncontrolled consumption.

SC-6 enforces explicit allocation limits on resources, structurally preventing the weakness from occurring.

Process isolation confines resource consumption to separate domains, reducing blast radius without stopping the root flaw.

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.IR-04 mostly match
prevents

Explicitly requires monitoring and maintaining resource capacity, directly addressing uncontrolled consumption to preserve availability.

DE.CM-09 partial match
prevents

Continuous monitoring of computing resources can detect resource exhaustion but does not itself enforce allocation limits.

PR.IR-03 partial match
prevents

Resilience mechanisms such as avoiding single points of failure indirectly reduce impact of resource exhaustion.

PR.PS-01 partial match
prevents

Hardened configuration baselines can include resource quotas and limits that constrain consumption.

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.

finds

Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.

prevents

By continuously monitoring utilization, stress-testing peak loads, and maintaining documented plans to scale or throttle resources, the control directly limits an attacker’s ability to drive a system into uncontrolled resource exhaustion.

finds

Pre-agreed severity-based prioritization and resource allocation during incident triage reduce the likelihood that an attacker-induced resource exhaustion will overwhelm the organization before corrective action is taken.

mitigates

Business-continuity plans that include resource-management controls reduce the likelihood that an attacker can trigger uncontrolled resource consumption by forcing the system into a degraded or fallback state.

mitigates

Defining RTOs and capacity requirements for ICT services during business-impact analysis forces organizations to provision sufficient resources and throttling mechanisms, reducing the likelihood that an attacker can induce denial-of-service through uncontrolled resource consumption.

finds

Early notification of anomalous resource consumption or system malfunctions enables throttling or isolation before availability is lost.

References