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CVE-2026-108357

Status: Awaiting AnalysisHigh (8.8)—
Severity8.8High · CVSS 4.0
Exploitation probability0.29 %higher than 20% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. From 3.3.0 until 3.10.8 and 5.10.0, Reader\Xml passes stored SpreadsheetML XML through XmlScanner::scan in Xml::canRead and Xml::trySimpleXMLLoadStringPrivate, while Xml::unentity decodes numeric entities only after each DOCTYPE pattern check. A double-encoded less-than character is reduced by the first callback to another encoded character and by the second callback to a literal less-than sign, so SimpleXML receives an unchecked DOCTYPE and entity declaration.

Read full descriptionShow less

Processing attacker-controlled SpreadsheetML XML can cause entity-expansion denial of service and can permit local file access or SSRF on PHP before 8.0 or when LIBXML_NOENT is enabled. This issue is fixed in versions 3.10.8 and 5.10.0.

CVSS

Base score
8.8
Version
4.0
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:L/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)

Probability of exploitation in the next 30 days
0.29 %
Percentile among all scored CVEs
20
Score date
10/23/2026

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 expone XML SpreadsheetML sin autenticación; el texto cita expansión de entidades (DoS) y acceso a archivos locales o SSRF solo en PHP<8.0 o con LIBXML_NOENT.

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

Filter Network TrafficVulnerability ScanningSSL/TLS InspectionPrivileged Account ManagementNetwork SegmentationNetwork Intrusion Prevention

Affected technologies (1)

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

Phpoffice — PhpspreadsheetAI

CWEs

References

Show 5 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-108357",
  "cveTags": [],
  "metrics": {
    "cvssMetricV40": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "Safety": "NOT_DEFINED",
          "version": "4.0",
          "Recovery": "NOT_DEFINED",
          "baseScore": 8.8,
          "Automatable": "NOT_DEFINED",
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:L/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": "HIGH",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "LOW",
          "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": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "PHPOffice",
          "product": "PhpSpreadsheet",
          "versions": [
            {
              "status": "affected",
              "version": ">= 3.3.0, < 3.10.8"
            },
            {
              "status": "affected",
              "version": ">= 4.0.0, < 5.10.0"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-10-22T18:17:26.377",
  "references": [
    {
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/commit/89f455c133e1a7e2d4abfadc43ce29eb7450d781",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294493856f1a25754f1e8a1d2185b93738",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.8",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.10.0",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-rxj4-h86g-25gc",
      "source": "security-advisories@github.com"
    }
  ],
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-611"
        },
        {
          "lang": "en",
          "value": "CWE-776"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. From 3.3.0 until 3.10.8 and 5.10.0, Reader\\Xml passes stored SpreadsheetML XML through XmlScanner::scan in Xml::canRead and Xml::trySimpleXMLLoadStringPrivate, while Xml::unentity decodes numeric entities only after each DOCTYPE pattern check. A double-encoded less-than character is reduced by the first callback to another encoded character and by the second callback to a literal less-than sign, so SimpleXML receives an unchecked DOCTYPE and entity declaration. Processing attacker-controlled SpreadsheetML XML can cause entity-expansion denial of service and can permit local file access or SSRF on PHP before 8.0 or when LIBXML_NOENT is enabled. This issue is fixed in versions 3.10.8 and 5.10.0."
    }
  ],
  "lastModified": "2026-10-23T19:42:24.553",
  "sourceIdentifier": "security-advisories@github.com"
}