CVE-2026-16192 in WebSphere Application Server
Summary
by MITRE • 07/28/2026
IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.8 is affected by a denial of service vulnerability when the restConnector-2.0 feature is enabled.
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Analysis
by VulDB Data Team • 07/29/2026
The vulnerability in IBM WebSphere Application Server Liberty versions 17.0.0.3 through 26.0.0.8 represents a critical denial of service condition that specifically impacts systems utilizing the restConnector-2.0 feature. This issue stems from insufficient input validation and error handling mechanisms within the REST connector implementation, creating a pathway for malicious actors to disrupt service availability. The affected versions span a significant portion of the Liberty server lifecycle, indicating this flaw has persisted across multiple major releases and likely affects organizations with extended support cycles.
The technical exploitation of this vulnerability occurs through crafted requests that trigger improper exception handling within the restConnector-2.0 component. When the feature is enabled and processing certain malformed HTTP requests, the server enters a state where it cannot properly handle subsequent legitimate requests, leading to complete service unavailability. This behavior manifests as thread exhaustion or resource depletion that prevents normal application processing. The vulnerability operates at the application layer and can be exploited remotely without authentication requirements, making it particularly dangerous in production environments where availability is paramount.
From an operational impact perspective, this vulnerability creates substantial business risk for organizations relying on IBM WebSphere Liberty servers for mission-critical applications. The denial of service condition results in complete service disruption that can affect multiple users simultaneously, potentially causing revenue loss and customer dissatisfaction. Organizations may experience extended downtime while applying patches or implementing workarounds, with the severity compounded by the fact that the vulnerability affects a core server feature that many applications depend upon for RESTful communication and management operations. The impact extends beyond immediate service interruption to include potential cascading failures in distributed systems where the Liberty server serves as an integration point.
Security professionals should reference CWE-400 for the underlying cause of uncontrolled resource consumption and consider ATT&CK technique T1499.004 for the specific denial of service vector targeting application availability. Organizations should immediately disable the restConnector-2.0 feature when not actively required, implement network-level rate limiting to reduce exploitation potential, and apply the latest IBM security patches as soon as available. Monitoring for unusual request patterns or resource consumption spikes should be implemented to detect potential exploitation attempts. The vulnerability highlights the importance of proper input validation and error handling in web application frameworks, emphasizing that even seemingly benign features can create significant security weaknesses when not properly secured against malformed inputs.