CVE-2026-17290 in API Connect
Summary
by MITRE • 11/07/2026
IBM API Connect 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 could allow a remote authenticated attacker to create unauthorized user accounts due to improper verification of cryptographic signatures. Identity information from a login provider is accepted without its signature being fully verified, so forged identity data could be used to create accounts.
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Analysis
by VulDB Data Team • 11/07/2026
The vulnerability identified in IBM API Connect versions 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 represents a critical flaw in the authentication and identity verification subsystem, specifically within the handling of external login provider credentials. This issue stems from an improper implementation of cryptographic signature validation mechanisms that are essential for ensuring the integrity and authenticity of user identity data transmitted during single sign-on or federated identity processes. When users attempt to log in via supported third-party providers such as SAML, OAuth, or OpenID Connect implementations, the system receives identity assertions containing claims about the user's attributes and role assignments. The core technical failure lies in the application’s logic which accepts these identity payloads without performing a complete verification of their digital signatures against trusted public keys or certificates. This oversight allows an attacker who possesses valid credentials for a compromised or controlled external identity provider to manipulate the payload content, effectively forging claims that grant elevated privileges or administrative access without possessing legitimate authorization from IBM API Connect itself.
From a technical perspective, this flaw aligns with CWE-347, which describes Improper Verification of Cryptographic Signature. In secure systems relying on federated authentication, the service provider must rigorously validate the signature embedded in security tokens to ensure they were issued by a trusted authority and have not been tampered with during transit. By skipping or inadequately performing this step, IBM API Connect fails to establish trust boundaries correctly. An attacker can intercept valid login requests from legitimate users or exploit misconfigured identity providers to inject malicious claims into the authentication flow. Because the system trusts these forged identities as authentic, it proceeds to provision new user accounts based on the manipulated data rather than rejecting them due to signature mismatch errors. This bypasses standard access control checks that would normally restrict account creation and privilege escalation to authorized administrators only.
The operational impact of this vulnerability is severe, primarily because it enables unauthorized account creation by remote authenticated attackers who have already gained some level of foothold within the identity ecosystem or can manipulate traffic between an identity provider and API Connect. Once a malicious actor successfully creates an unauthorized user account with elevated privileges, they gain persistent access to the management plane of IBM API Connect. This compromises the confidentiality, integrity, and availability of all APIs managed by the platform. Attackers could exfiltrate sensitive data protected behind these APIs, modify or delete critical configurations, disrupt service availability through resource exhaustion, or use the compromised instance as a pivot point for further lateral movement within the enterprise network. The ability to create arbitrary accounts also undermines audit trails and accountability measures, making forensic analysis significantly more difficult since malicious actions can be attributed to non-existent or spoofed user identities.
This vulnerability maps directly to MITRE ATT&CK technique T1078, specifically Valid Accounts, as it involves gaining access using legitimate credentials that have been manipulated or forged through identity provider compromise. It also relates to T1136, Create Account, where the attacker establishes a new entry in the system’s directory to maintain persistence and expand their attack surface without detection by traditional credential-based monitoring tools. The exploitation path typically requires initial network-level access to intercept or modify authentication traffic if direct control of an identity provider is not available, but once achieved, it allows for significant privilege escalation from standard user roles to administrative levels depending on the claims injected into the forged token.
Mitigation strategies must focus on immediate patching and rigorous configuration review. Organizations running affected versions should apply IBM’s official security updates that correct the signature verification logic in their respective release streams. Until patches are applied, administrators can implement network-level controls such as strict firewall rules to limit communication between API Connect nodes and identity providers only through trusted channels with mutual TLS authentication enabled at the transport layer. Additionally, enabling enhanced logging for authentication events allows security operations centers to detect anomalies indicative of signature verification failures or unusual account creation patterns. Regular audits of user accounts and permissions should be conducted to identify any unauthorized entries that may have been created during exploitation windows. Long-term remediation involves adopting a zero-trust architecture where every identity assertion is verified independently regardless of its source, ensuring that cryptographic integrity checks are never bypassed for performance convenience or configuration oversights.