CVE-2026-15412 in WebSphere Application Server
Summary
by MITRE • 09/14/2026
IBM WebSphere Application Server 9.0, and 8.5 and IBM WebSphere Application Server - Liberty could allow a remote attacker to conduct phishing attacks, using an open redirect attack. By persuading a victim to visit a specially crafted Web site, a remote attacker could exploit this vulnerability to spoof the URL displayed to redirect a user to a malicious Web site that would appear to be trusted. This could allow the attacker to obtain highly sensitive information or conduct further attacks against the victim.
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Analysis
by VulDB Data Team • 09/14/2026
The identified vulnerability in IBM WebSphere Application Server versions 9.0 and 8.5, as well as the Liberty profile variant, constitutes a critical security flaw centered on open redirect functionality. This issue arises from insufficient validation of user-supplied input within URL redirection parameters handled by the application server's web container or associated administrative interfaces. When an attacker crafts a malicious link containing a specifically designed target URL parameter, the server fails to adequately verify whether the destination is part of a trusted domain list. Consequently, instead of restricting redirects to internal resources or explicitly whitelisted external sites, the software blindly executes the redirection instruction provided by the client request. This lack of rigorous input sanitization allows an adversary to manipulate the redirect mechanism to point toward arbitrary domains under their control rather than legitimate application endpoints.
The operational impact of this vulnerability is primarily facilitative for social engineering and phishing campaigns. By exploiting the open redirect, a remote attacker can create deceptive URLs that appear to originate from or lead directly through IBM WebSphere Application Server infrastructure. Because the initial part of the URL displays the trusted domain name of the victim organization's server before redirecting, users are likely to trust the link based on visual cues in their browser address bar. Once clicked, the user is seamlessly transported to a malicious website designed to mimic legitimate services or harvest credentials. This technique significantly lowers the barrier for attackers to conduct sophisticated phishing attacks, as it bypasses many basic security warnings that browsers might otherwise display when navigating directly to an untrusted domain from an unrelated source.
From a classification perspective, this vulnerability aligns with CWE-601, which defines URL Redirection to Untrusted Site (Open Redirect). The exploitation strategy leverages the trust relationship users have with known domains, effectively weaponizing that trust against them. In terms of offensive security frameworks such as MITRE ATT&CK, this behavior is categorized under Tactic TA0001 Initial Access and specifically Technique T1566 Phishing. More precisely, it falls under Sub-technique T1566.002 Spearphishing Link, where the attacker uses a link to lure victims into performing actions that compromise their security posture. The vulnerability does not typically result in direct system compromise or data exfiltration on its own but serves as a critical vector for initiating broader attack chains involving credential theft and subsequent lateral movement within an organization's network.
Mitigation strategies must focus on implementing strict validation controls at the application server level. Administrators should ensure that any redirection functionality explicitly validates the target URL against a predefined whitelist of allowed domains or paths before executing the redirect operation. If dynamic redirects are necessary, developers should encode user input and avoid passing raw URLs directly into redirect parameters without verification. Additionally, IBM has released security updates for these affected versions to address this flaw; therefore, applying the latest available patches is the primary remediation step. Organizations should also consider implementing Content Security Policy headers that restrict frame ancestors and navigation targets where applicable, adding an additional layer of defense against clickjacking and redirect-based attacks. Regular auditing of web application configurations and penetration testing for open redirects are recommended to maintain a robust security posture against such social engineering vectors.