External risk intelligence

IBM WebSphere Extreme Scale Security Bypass Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.1)

CVE-2026-101117

IBM WebSphere Extreme Scale is a middleware product often used to support web applications and services. While it can exist in internal tiers, it is commonly deployed as part of public-facing web or application infrastructure, making it a plausible target for external exposure in common network architectures.

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A security vulnerability has been identified in IBM WebSphere Extreme Scale, a component used in many applications and services. This issue could allow unauthorized access by bypassing security measures due to a misconfiguration in how the system handles web content. The primary concern is to confirm if our organization uses this technology and is therefore potentially exposed.

Improper web content rules create security gaps.
It affects a widely used application component.
Confirm exposure and relevance to our environment.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending specially crafted requests to a vulnerable IBM WebSphere Extreme Scale instance. If successful, the improper Content Security Policy configuration could allow the attacker to bypass security restrictions, potentially leading to unauthorized access or modification of data.

Unauthenticated network access required.
Exploits an insecure Content Security Policy.
Risk of unauthorized access or data alteration.

Live Threat

Current exploitation, exposure, and threat context

IBM WebSphere Extreme Scale, when improperly configured with its Content Security Policy, could allow unauthenticated remote attackers to bypass security restrictions. This bypass may affect the intended security posture of applications relying on this configuration.

Bypassed security restrictions.
Improper Content Security Policy.
Potential unauthorized access.

Operational Fix

Recommended remediation, mitigation, and detection steps

IBM WebSphere Extreme Scale instances with improper Content Security Policy configuration are likely managed by application owners or platform teams, with oversight from network and security teams. The first practical step is to identify all deployed instances, determine their exposure and criticality, and assign an owner for remediation planning.

Identify affected instances and their owners.
Verify network reachability and business impact.
Plan remediation actions based on risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is IBM WebSphere Extreme Scale?

It is a middleware platform designed to provide high-performance, elastic caching and grid computing capabilities. Organizations use it to manage massive amounts of data in memory, ensuring that complex web applications and services remain fast and scalable even under heavy loads.

What does CVE-2026-101117 mean for security?

This vulnerability involves a weakness classified as CWE-16, which relates to general configuration errors. In this case, the software fails to properly enforce Content Security Policy (CSP) rules. This flaw allows an attacker to bypass intended security restrictions, potentially manipulating how the browser interacts with the application.

How does an attacker trigger this vulnerability?

An attacker triggers this by sending specially crafted network requests to the target service. The vulnerability relies on the absence of proper security constraints, meaning it does not require user interaction or pre-existing authentication to be effective.

Is my IBM WebSphere Extreme Scale instance at risk?

According to Halo Surface Signal, this software is often deployed as part of public-facing web infrastructure, which increases the likelihood of external exposure. If your instance is accessible via the internet, it is at higher risk than those isolated within internal, restricted network segments.

What are the first steps to address this issue?

Start by auditing your environment to map where IBM WebSphere Extreme Scale is deployed. Once identified, consult your platform or application owners to determine which instances are internet-facing. Finally, evaluate the configuration of your Content Security Policies to plan necessary hardening updates.

References

www.ibm.com/support/pages/node/7293764

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.