Description

IBM API Connect 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 could allow an unauthenticated attacker to bypass authentication due to improper verification of a cryptographic signature.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-11-07T05:18:37.913Z",
  "pubdate": "2026-11-07T05:18:37.913Z",
  "executiveSummary": "This vulnerability is an authentication bypass flaw affecting specific versions of IBM API Connect. The root cause is identified as an improper verification of a cryptographic signature, which undermines the integrity and authenticity checks required for user session validation.\nBy exploiting this flaw, an unauthenticated, remote attacker can successfully circumvent authentication protocols. This allows unauthorized access to protected API resources and administrative interfaces, effectively bypassing security controls designed to guard sensitive endpoints.\nAffected products include IBM API Connect versions 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2. The risk associated with this vulnerability is high, as it permits threat actors to gain unauthorized access without valid credentials. Successful exploitation compromises the confidentiality and integrity of the API ecosystem. No user interaction or elevated privileges are required for an attacker to initiate the exploitation process, making it a significant threat to internal and external API security posture.",
  "technicalDetails": "The vulnerability resides within the cryptographic validation logic responsible for verifying digital signatures used in the authentication process of IBM API Connect. Cryptographic signatures are fundamental to establishing the legitimacy of authentication tokens or requests. When the validation routine fails to correctly implement or verify these signatures, the system may inadvertently accept tampered or forged authentication materials as valid.\nThe exploitation flow begins when an unauthenticated attacker transmits a crafted request to a protected endpoint within the IBM API Connect platform. Instead of providing legitimate credentials, the attacker leverages the flaw in the signature verification mechanism. Because the verification routine does not properly validate the cryptographic signature, the underlying service assumes the request is cryptographically sound and authorized.\nThis bypass implies that the authentication middleware lacks sufficient strictness when checking identity assertions. If the system relies on signed JSON Web Tokens (JWT) or similar cryptographic structures for session management, the attacker can manipulate the request parameters or the payload itself, provided they can bypass the signature check that would otherwise detect such unauthorized modifications.\nThe vulnerability specifically affects versions 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2. The exposure exists across all network interfaces where the vulnerable authentication endpoint is reachable. Since the flaw occurs before the application level security controls successfully finalize an identity, the attacker effectively escalates their access to that of a legitimate, authenticated user or administrator, depending on the scope of the token or the context of the bypass.\nPost-exploitation, an attacker can perform any action authorized to the identity they have impersonated or assumed. This includes unauthorized retrieval of sensitive configuration data, manipulation of API definitions, unauthorized access to backend services connected through the API gateway, or potentially full administrative control over the API Connect environment. Given that this is a flaw in the core security verification logic, there is no mitigation available through standard application-level configuration; it requires structural fixes to the signature verification code path."
}