CVE-2026-93475

Status: ReceivedCritical (9.3)—
Severity9.3Critical · CVSS 4.0
Exploitation probability—next 30 days
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

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.

CVSS

Base score
9.3
Version
4.0
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Exploitation probability (EPSS)

FIRST hasn't scored this CVE yet (usual for very recent or rejected CVEs).

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

Vector AV:N/PR:N/UI:N y escritura fuera de límites (CWE-787) en verificación de cadena; el texto no menciona ejecución de comandos, así que no se asigna T1059 pese a la pista.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

ATT&CK mitigations that cover these techniques

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

CWEs

References

Show 1 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-93475",
  "cveTags": [],
  "metrics": {
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        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-93475",
          "role": "CISA Coordinator",
          "options": [
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              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
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          "version": "2.0.3",
          "timestamp": "2026-10-20T17:02:43.642743Z"
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    "cvssMetricV40": [
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          "Automatable": "NOT_DEFINED",
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          "baseSeverity": "CRITICAL",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "exploitMaturity": "NOT_DEFINED",
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          "modifiedAttackVector": "NOT_DEFINED",
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          "modifiedUserInteraction": "NOT_DEFINED",
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          "modifiedAttackRequirements": "NOT_DEFINED",
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          "modifiedSubIntegrityImpact": "NOT_DEFINED",
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          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
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  "affected": [
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      "source": "emo@eclipse.org",
      "affectedData": [
        {
          "vendor": "Eclipse Foundation",
          "product": "Eclipse ThreadX - NetX Duo",
          "versions": [
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              "version": "0",
              "versionType": "semver",
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              "version": "6.5.2.202603"
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  "published": "2026-10-20T16:17:17.520",
  "references": [
    {
      "url": "https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-rcv5-vfff-25gh",
      "source": "emo@eclipse.org"
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    {
      "lang": "en",
      "value": "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.\n\n\n\nIt 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."
    }
  ],
  "lastModified": "2026-10-20T18:17:23.060",
  "sourceIdentifier": "emo@eclipse.org"
}