CVE-2026-101294 in WebSphere Application Server
Summary
by MITRE • 10/15/2026
IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.10 and IBM WebSphere Application Server 8.5, and 9.0 could allow a remote attacker to bypass cryptographic signature verification due to improper verification of cryptographic signature.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 10/15/2026
The vulnerability identified in IBM WebSphere Application Server Liberty versions ranging from 17.0.0.3 through 26.0.0.10, as well as the traditional editions of IBM WebSphere Application Server version 8.5 and 9.0, represents a critical failure in cryptographic integrity verification mechanisms. This flaw allows remote attackers to bypass signature validation processes that are essential for ensuring the authenticity and non-repudiation of data exchanged within the application server environment. The core technical deficiency lies in the improper handling or verification logic applied when processing digital signatures associated with incoming requests, configuration files, or deployed modules. Instead of strictly enforcing cryptographic checks against trusted public keys or certificates, the affected software exhibits a lapse that permits malformed or tampered payloads to be accepted as valid without triggering appropriate rejection protocols.
From a technical perspective, this issue aligns closely with CWE-347, which describes Improper Verification of Cryptographic Signature. In secure systems, cryptographic signatures serve as a guarantee that data has not been altered in transit and originates from a trusted source. When the verification process is flawed, an attacker can manipulate request parameters or intercept communication channels to inject malicious code or alter administrative commands without detection. The vulnerability likely stems from insufficient validation of signature algorithms, improper handling of certificate chains, or logic errors in comparing expected versus actual hash values during the parsing phase of HTTP requests or internal module loading procedures. This creates a pathway for attackers to subvert security controls that rely on these signatures for authorization and integrity assurance.
The operational impact of this vulnerability is severe, particularly given the role WebSphere plays as an enterprise-grade application server hosting critical business applications. A successful exploitation could lead to unauthorized access to sensitive data, remote code execution if combined with other vulnerabilities in deployed applications, or complete compromise of the underlying infrastructure by bypassing authentication and authorization layers that depend on signed tokens or configurations. Attackers operating remotely can exploit this weakness to perform privilege escalation, modify application behavior dynamically, or disrupt service availability by injecting malicious payloads that appear legitimate due to the failed signature check. This undermines the trust model inherent in secure web services and exposes organizations to significant risk of data breaches and regulatory non-compliance.
Mitigation strategies must prioritize immediate patching to the latest fixed versions provided by IBM for both WebSphere Application Server Liberty and traditional editions. Organizations should also implement network-level controls such as strict ingress filtering and intrusion detection systems configured to identify anomalous patterns consistent with signature bypass attempts, although these are compensatory measures rather than fixes. Additionally, reviewing application code that relies on cryptographic verification ensures that custom implementations do not introduce similar weaknesses. Adhering to industry standards like the Common Weakness Enumeration for proper input validation and following ATT&CK techniques related to defense evasion can help in monitoring for exploitation attempts while patches are being deployed across the infrastructure.