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CVE-2026-6594

Full vulnerability record from the local CVENow database.

Description

A vulnerability was determined in brikcss merge up to 1.3.0. This affects an unknown part. Executing a manipulation of the argument __proto__/constructor.prototype/prototype can lead to improperly controlled modification of object prototype attributes. The attack may be performed from remote. The vendor was contacted early about this disclosure but did not respond in any way.

Severity
MEDIUM
CVSS score
6.9 (v4.0)
Vulnerability status
Deferred
Source identifier
Published
2026-04-20 02:16:15.633000
Last modified
2026-10-26 21:10:00.170000
View original CVE JSON
{
  "id": "CVE-2026-6594",
  "sourceIdentifier": "[email protected]",
  "published": "2026-04-20T02:16:15.633",
  "lastModified": "2026-10-26T21:10:00.170",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A vulnerability was determined in brikcss merge up to 1.3.0. This affects an unknown part. Executing a manipulation of the argument __proto__/constructor.prototype/prototype can lead to improperly controlled modification of object prototype attributes. The attack may be performed from remote. The vendor was contacted early about this disclosure but did not respond in any way."
    },
    {
      "lang": "es",
      "value": "Se determinó una vulnerabilidad en brikcss merge hasta 1.3.0. Esto afecta una parte desconocida. La ejecución de una manipulación del argumento __proto__/constructor.prototype/prototype puede llevar a una modificación indebidamente controlada de atributos de prototipo de objetos. El ataque puede realizarse de forma remota. El proveedor fue contactado tempranamente sobre esta divulgación, pero no respondió de ninguna manera."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "brikcss",
          "product": "merge",
          "versions": [
            {
              "version": "1.0",
              "status": "affected"
            },
            {
              "version": "1.1",
              "status": "affected"
            },
            {
              "version": "1.2",
              "status": "affected"
            },
            {
              "version": "1.3.0",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/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",
          "baseScore": 6.9,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "LOW",
          "vulnAvailabilityImpact": "LOW",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
          "baseScore": 7.3,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.4
      }
    ],
    "cvssMetricV2": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "2.0",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
          "baseScore": 7.5,
          "accessVector": "NETWORK",
          "accessComplexity": "LOW",
          "authentication": "NONE",
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "PARTIAL",
          "availabilityImpact": "PARTIAL"
        },
        "baseSeverity": "HIGH",
        "exploitabilityScore": 10.0,
        "impactScore": 6.4,
        "acInsufInfo": false,
        "obtainAllPrivilege": false,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-04-20T14:53:05.141628Z",
          "id": "CVE-2026-6594",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-94"
        },
        {
          "lang": "en",
          "value": "CWE-1321"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/sudo-secure/security-research/blob/main/brikcss-merge/prototype-pollution/PoC.md",
      "source": "[email protected]"
    },
    {
      "url": "https://vuldb.com/submit/791805",
      "source": "[email protected]"
    },
    {
      "url": "https://vuldb.com/vuln/358229",
      "source": "[email protected]"
    },
    {
      "url": "https://vuldb.com/vuln/358229/cti",
      "source": "[email protected]"
    }
  ]
}