Out-of-Bounds Write Vulnerability in NetX Secure's X.509 Parser

CVE-2026-93475

What is CVE-2026-93475?

The X.509 parser in NetX Secure allows for the acceptance of RSA public keys of any size, resulting in a serious vulnerability during signature verification. When a certificate with a larger modulus is processed, the decryption occurs into fixed-size buffers meant for a maximum RSA modulus size of 4096 bits. This enables out-of-bounds writing, which occurs during standard certificate-chain verification. The vulnerability is exploitable pre-authentication. Attackers can leverage this by supplying an oversized key as part of a deceptive certificate chain, targeting both TLS and DTLS protocols. This could lead to critical security breaches in environments relying on client or server certificate authentication.

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