{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-123568", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-11-06T00:53:14.312Z", "datePublished": "2026-11-08T01:38:06.526Z", "dateUpdated": "2026-11-08T01:38:06.526Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-11-08T01:38:06.526Z"}, "datePublic": "2026-02-18T00:00:00.000Z", "title": "Sveltejs devalue before 5.6.3 Prototype Pollution via uneval Output", "descriptions": [{"lang": "en", "value": "Sveltejs devalue before 5.6.3 contains a prototype pollution vulnerability that allows attackers to alter object prototypes by supplying untrusted data to uneval. When the generated code is later evaluated, it creates objects with polluted prototypes, producing output data whose shape differs from the original input."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')", "cweId": "CWE-1321", "type": "CWE"}]}], "affected": [{"vendor": "sveltejs", "product": "devalue", "defaultStatus": "unaffected", "packageURL": "pkg:npm/devalue", "versions": [{"version": "0", "status": "affected", "versionType": "semver", "lessThan": "5.6.3"}, {"version": "5.6.3", "status": "unaffected", "versionType": "semver"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:svelte:devalue:*:*:*:*:*:*:*:*", "versionEndExcluding": "5.6.3"}]}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "HIGH", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "subAvailabilityImpact": "NONE", "baseScore": 2.1, "baseSeverity": "LOW"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE", "baseScore": 4.4, "baseSeverity": "MEDIUM"}}], "references": [{"url": "https://github.com/sveltejs/devalue/security/advisories/GHSA-8qm3-746x-r74r", "tags": ["vendor-advisory"], "name": "GitHub Security Advisory (GHSA-8qm3-746x-r74r)"}, {"name": "VulnCheck Advisory: Sveltejs devalue before 5.6.3 Prototype Pollution via uneval Output", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/sveltejs-devalue-before-5.6.3-prototype-pollution-via-uneval-output"}], "credits": [{"lang": "en", "value": "elliott-with-the-longest-name-on-github", "type": "remediation developer"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:npm/devalue", "product": "devalue", "vendor": "sveltejs", "versions": [{"lessThan": "5.6.3", "status": "affected", "version": "0", "versionType": "semver"}, {"status": "unaffected", "version": "5.6.3", "versionType": "semver"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Sveltejs devalue before 5.6.3 contains a prototype pollution vulnerability that allows attackers to alter object prototypes by supplying untrusted data to uneval. When the generated code is later evaluated, it creates objects with polluted prototypes, producing output data whose shape differs from the original input."}], "id": "CVE-2026-123568", "lastModified": "2026-11-08T02:16:49.513", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "HIGH", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 1.3, "impactScore": 2.7, "source": "disclosure@vulncheck.com", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 2.1, "baseSeverity": "LOW", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "HIGH", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}]}, "published": "2026-11-08T02:16:49.513", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/sveltejs/devalue/security/advisories/GHSA-8qm3-746x-r74r"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/sveltejs-devalue-before-5.6.3-prototype-pollution-via-uneval-output"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-1321"}], "source": "disclosure@vulncheck.com", "type": "Primary"}]}

{}