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CVE-2026-53783

Full vulnerability record from the local CVENow database.

Description

rsync before 3.5.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability in the rrsync restricted shell wrapper that allows authenticated clients to escape enforced directory restrictions by substituting a symlink for a path component after validation but before transfer processing. Attackers can additionally leverage unrestricted flags such as --copy-unsafe-links, -D, and --log-file through rrsync to read or write files outside the permitted directory subtree.

Severity
HIGH
CVSS score
8.6 (v4.0)
Vulnerability status
Awaiting Analysis
Source identifier
Published
2026-08-13 15:19:41.913000
Last modified
2026-10-24 16:10:00.153000
View original CVE JSON
{
  "id": "CVE-2026-53783",
  "sourceIdentifier": "[email protected]",
  "published": "2026-08-13T15:19:41.913",
  "lastModified": "2026-10-24T16:10:00.153",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "rsync before 3.5.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability in the rrsync restricted shell wrapper that allows authenticated clients to escape enforced directory restrictions by substituting a symlink for a path component after validation but before transfer processing. Attackers can additionally leverage unrestricted flags such as --copy-unsafe-links, -D, and --log-file through rrsync to read or write files outside the permitted directory subtree."
    },
    {
      "lang": "es",
      "value": "rsync anterior a la versión 3.5.0 contiene una vulnerabilidad de condición de carrera de tiempo de verificación a tiempo de uso (TOCTOU) en el envoltorio de shell restringido rrsync que permite a clientes autenticados evadir las restricciones de directorio impuestas al sustituir un enlace simbólico por un componente de ruta después de la validación pero antes del procesamiento de la transferencia. Los atacantes pueden aprovechar adicionalmente opciones no restringidas como --copy-unsafe-links, -D y --log-file a través de rrsync para leer o escribir archivos fuera del subárbol de directorio permitido."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "RsyncProject",
          "product": "rsync",
          "defaultStatus": "unaffected",
          "repo": "https://github.com/RsyncProject/rsync",
          "packageURL": "pkg:github/RsyncProject/rsync",
          "versions": [
            {
              "version": "0",
              "lessThanOrEqual": "3.4.4",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "3.5.0",
              "versionType": "semver",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/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",
          "baseScore": 8.6,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnAvailabilityImpact": "NONE",
          "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:L/UI:N/S:U/C:H/I:H/A:N",
          "baseScore": 8.1,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.2
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-14T15:41:11.374187Z",
          "id": "CVE-2026-53783",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-59"
        },
        {
          "lang": "en",
          "value": "CWE-88"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/RsyncProject/rsync/releases/tag/v3.5.0",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/RsyncProject/rsync/security/advisories/GHSA-9cgc-64g4-3gv5",
      "source": "[email protected]"
    },
    {
      "url": "https://www.vulncheck.com/advisories/rsync-toctou-race-condition-directory-escape-via-rrsync",
      "source": "[email protected]"
    }
  ]
}