CVE-2026-11929 in Verify Identity Access
Summary
by MITRE • 09/15/2026
IBM Security Verify Identity Access Reverse Proxy in certain configurations may provide weaker than expected cryptographic validation of user supplied data.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability identified within IBM Security Verify Identity and Access Management's reverse proxy component represents a significant deviation from established cryptographic best practices, specifically concerning the integrity verification of incoming requests. In specific configuration scenarios, the system fails to enforce rigorous validation protocols for user-supplied data before it is processed or forwarded. This weakness stems from an insufficient implementation of message authentication codes or digital signatures during the handshake and request forwarding phases. Instead of ensuring that every piece of data originating from a client has been cryptographically bound to the session context using strong, non-reversible algorithms with proper key management, the system may accept modified payloads if they meet looser structural criteria rather than strict cryptographic proofs. This flaw effectively undermines the trust boundary between the reverse proxy and the backend identity services, allowing an attacker who can intercept or manipulate network traffic to alter request parameters without detection by the immediate validation layer.
From a technical perspective, this issue aligns with CWE-347, which describes Improper Verification of Cryptographic Signature. The core deficiency lies in the application's logic for validating incoming HTTP requests that are proxied through IBM Security Verify. When a reverse proxy operates, it acts as an intermediary, often terminating TLS connections from clients and establishing new ones to backend servers. If the mechanism used to verify the authenticity or integrity of these forwarded messages relies on weak checksums, predictable nonces, or lacks signature verification entirely for certain data types, an attacker can perform a man-in-the-middle attack to modify claims, tokens, or authentication headers. For instance, if JSON Web Tokens (JWT) or SAML assertions are passed through the proxy without strict cryptographic validation of their payload against expected signatures, an adversary could alter user roles, expiration times, or identity attributes embedded within these structures. The vulnerability is particularly dangerous because it exploits the implicit trust placed in the reverse proxy to sanitize and validate inputs before they reach critical authentication logic.
The operational impact of this weakness is severe, potentially leading to complete compromise of access control mechanisms. An attacker exploiting this flaw could escalate privileges by modifying role assignments or group memberships within identity tokens, thereby gaining administrative access to sensitive applications protected by IBM Security Verify. Furthermore, the ability to manipulate user-supplied data without cryptographic validation facilitates session hijacking and impersonation attacks. Since the reverse proxy is a central point of entry for many enterprise authentication flows, compromising its integrity verification allows an attacker to bypass multi-factor authentication checks or inject malicious payloads into downstream services that trust the proxied requests as legitimate. This can result in unauthorized access to confidential data, financial fraud through manipulated transaction details, and broader lateral movement within the network infrastructure once initial foothold is established via compromised credentials derived from these altered tokens.
Mitigation strategies must focus on enforcing strict cryptographic standards across all proxy configurations. Administrators should review their reverse proxy settings to ensure that only strong hash algorithms such as SHA-256 or stronger are used for any integrity checks, and that digital signatures using RSA with PSS padding or ECDSA are mandated for token validation rather than simple checksums. It is critical to verify that the configuration explicitly requires signature verification for all incoming SAML assertions, JWTs, and OAuth tokens passing through the proxy. IBM has likely released patches addressing this specific implementation flaw; therefore, applying the latest security updates provided by IBM Security Verify is essential. Additionally, organizations should implement network-level protections such as mutual TLS (mTLS) between clients and the reverse proxy to ensure that even if application-layer validation fails, the transport layer provides an additional barrier against tampering. Regular auditing of authentication logs for anomalies in token structures or unexpected changes in user attributes can also help detect exploitation attempts early.