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CVE-2026-90447

Status: Awaiting AnalysisHigh (7.1)—

A routing rule selects between two different authentication mechanisms for the same downstream service based on the value of a client-supplied request header, rather than on any property the client cannot control. An authenticated user in possession of a shared service credential can set this header to route around the primary role-based authorization check and reach the alternate path's fixed, elevated role instead. This allows a low-privileged authenticated attacker who knows the shared credential to perform actions reserved for a higher-privileged role.

CVSS

Exploitation probability (EPSS)

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.

AV:N y PR:L: acceso remoto con autenticación. La pista sugiere T1210, pero el texto describe manipulación de cabecera HTTP para eludir autorización, no explotación de servicio remoto vulnerable. Sin embargo, T1190 requeriría acceso sin autenticación. T1068 es escalada local. El impacto principal es

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

Privileged Account ManagementApplication Developer GuidanceActive Directory ConfigurationVulnerability ScanningUser TrainingUser Account Management

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2026-90447",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-90447",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-14T16:14:01.854681Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "ics-cert@hq.dhs.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 6.5,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 2.8
      }
    ],
    "cvssMetricV40": [
      {
        "type": "Secondary",
        "source": "ics-cert@hq.dhs.gov",
        "cvssData": {
          "Safety": "NOT_DEFINED",
          "version": "4.0",
          "Recovery": "NOT_DEFINED",
          "baseScore": 7.1,
          "Automatable": "NOT_DEFINED",
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/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",
          "providerUrgency": "NOT_DEFINED",
          "userInteraction": "NONE",
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          "attackRequirements": "NONE",
          "privilegesRequired": "LOW",
          "subIntegrityImpact": "NONE",
          "vulnIntegrityImpact": "HIGH",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "confidentialityRequirement": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
        }
      }
    ]
  },
  "affected": [
    {
      "source": "ics-cert@hq.dhs.gov",
      "affectedData": [
        {
          "repo": "https://github.com/cisagov/Malcolm",
          "vendor": "CISA",
          "product": "Malcolm",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "v26.06.0",
              "versionType": "custom"
            },
            {
              "status": "unaffected",
              "version": "v26.06.0"
            }
          ],
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      ]
    }
  ],
  "published": "2026-09-11T22:16:46.797",
  "references": [
    {
      "url": "https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26-254-01.json",
      "source": "ics-cert@hq.dhs.gov"
    },
    {
      "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-26-254-01",
      "source": "ics-cert@hq.dhs.gov"
    }
  ],
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "ics-cert@hq.dhs.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-290"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A routing rule selects between two different authentication mechanisms for the same downstream service based on the value of a client-supplied request header, rather than on any property the client cannot control. An authenticated user in possession of a shared service credential can set this header to route around the primary role-based authorization check and reach the alternate path's fixed, elevated role instead. This allows a low-privileged authenticated attacker who knows the shared credential to perform actions reserved for a higher-privileged role."
    }
  ],
  "lastModified": "2026-10-02T22:16:55.190",
  "sourceIdentifier": "ics-cert@hq.dhs.gov"
}