Description
The X.509 parser in NetX Secure accepts an RSA public key of any size, but every signature-verification path decrypts into fixed-size buffers dimensioned for the `NX_CRYPTO_MAX_RSA_MODULUS_SIZE` default of 4096 bits. A certificate carrying a larger modulus drives an out-of-bounds write past a file-scope static during ordinary certificate-chain verification.



It is reachable pre-authentication. The issuer used for the crypto operation is looked up in the remote, peer-supplied store before the trusted store, so the attacker supplies the oversized key themselves as an intermediate in the chain they present. It triggers on a TLS or DTLS client verifying a malicious server's chain, and on a server performing client-certificate authentication.
Published: 2026-10-20
Score: 9.3 Critical
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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History

Tue, 20 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
Description The X.509 parser in NetX Secure accepts an RSA public key of any size, but every signature-verification path decrypts into fixed-size buffers dimensioned for the `NX_CRYPTO_MAX_RSA_MODULUS_SIZE` default of 4096 bits. A certificate carrying a larger modulus drives an out-of-bounds write past a file-scope static during ordinary certificate-chain verification. It is reachable pre-authentication. The issuer used for the crypto operation is looked up in the remote, peer-supplied store before the trusted store, so the attacker supplies the oversized key themselves as an intermediate in the chain they present. It triggers on a TLS or DTLS client verifying a malicious server's chain, and on a server performing client-certificate authentication.
Title Out-of-bounds Write via an Unbounded RSA Modulus in NetX Secure X.509
Weaknesses CWE-1284
CWE-787
References
Metrics cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: eclipse

Published:

Updated: 2026-10-20T15:04:30.044Z

Reserved: 2026-09-23T13:42:24.314Z

Link: CVE-2026-93475

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-20T16:17:17.520

Modified: 2026-10-20T16:17:17.520

Link: CVE-2026-93475

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-1284

    Improper Validation of Specified Quantity in Input

  • CWE-787

    Out-of-bounds Write