« Volver al listado

CVE-2026-32853

Estado: AnalizadaMedia (6.9)—

LibVNCServer versions 0.9.15 and prior (fixed in commit 009008e) contain a heap out-of-bounds read vulnerability in the UltraZip encoding handler that allows a malicious VNC server to cause information disclosure or application crash. Attackers can exploit improper bounds checking in the HandleUltraZipBPP() function by manipulating subrectangle header counts to read beyond the allocated heap buffer.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

Libvncserver Project — Libvncserver

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-32853",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-32853",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-03-25T13:41:12.751342Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.1,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.2,
        "exploitabilityScore": 2.8
      }
    ],
    "cvssMetricV40": [
      {
        "type": "Secondary",
        "source": "disclosure@vulncheck.com",
        "cvssData": {
          "Safety": "NOT_DEFINED",
          "version": "4.0",
          "Recovery": "NOT_DEFINED",
          "baseScore": 6.9,
          "Automatable": "NOT_DEFINED",
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/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",
          "exploitMaturity": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "subIntegrityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "vulnAvailabilityImpact": "LOW",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "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": "disclosure@vulncheck.com",
      "affectedData": [
        {
          "repo": "https://github.com/LibVNC/libvncserver",
          "vendor": "LibVNC",
          "product": "LibVNCServer",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "versionType": "semver",
              "lessThanOrEqual": "0.9.15"
            },
            {
              "status": "unaffected",
              "version": "009008e2f4d5a54dd71f422070df3af7b3dbc931",
              "versionType": "git"
            }
          ],
          "packageURL": "pkg:github/LibVNC/libvncserver",
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-03-24T18:16:09.253",
  "references": [
    {
      "url": "https://github.com/LibVNC/libvncserver/commit/009008e2f4d5a54dd71f422070df3af7b3dbc931",
      "tags": [
        "Patch"
      ],
      "source": "disclosure@vulncheck.com"
    },
    {
      "url": "https://github.com/LibVNC/libvncserver/security/advisories/GHSA-87q7-v983-qwcj",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "disclosure@vulncheck.com"
    },
    {
      "url": "https://www.vulncheck.com/advisories/libvncserver-ultrazip-encoding-heap-out-of-bounds-read",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "source": "disclosure@vulncheck.com"
    },
    {
      "url": "https://github.com/LibVNC/libvncserver/security/advisories/GHSA-87q7-v983-qwcj",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "disclosure@vulncheck.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "LibVNCServer versions 0.9.15 and prior (fixed in commit 009008e) contain a heap out-of-bounds read vulnerability in the UltraZip encoding handler that allows a malicious VNC server to cause information disclosure or application crash. Attackers can exploit improper bounds checking in the HandleUltraZipBPP() function by manipulating subrectangle header counts to read beyond the allocated heap buffer."
    },
    {
      "lang": "es",
      "value": "Las versiones 0.9.15 y anteriores de LibVNCServer (corregido en el commit 009008e) contienen una vulnerabilidad de lectura fuera de límites de la pila en el gestor de codificación UltraZip que permite a un servidor VNC malicioso causar revelación de información o un fallo de la aplicación. Los atacantes pueden explotar la comprobación de límites incorrecta en la función HandleUltraZipBPP() manipulando los recuentos de encabezados de subrectángulos para leer más allá del búfer de pila asignado."
    }
  ],
  "lastModified": "2026-07-14T19:16:57.773",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:libvncserver_project:libvncserver:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A73C0099-80A6-4B55-8B34-7968BFADE90A",
              "versionEndExcluding": "0.9.15"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "disclosure@vulncheck.com"
}