CVE-2026-30821

{"id": "CVE-2026-30821", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.2, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/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", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "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"}}]}, "published": "2026-03-07T05:16:26.907", "references": [{"url": "https://github.com/FlowiseAI/Flowise/releases/tag/flowise%403.0.13", "tags": ["Product", "Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-j8g8-j7fc-43v6", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-434"}]}], "descriptions": [{"lang": "en", "value": "Flowise is a drag & drop user interface to build a customized large language model flow. Prior to version 3.0.13, the /api/v1/attachments/:chatflowId/:chatId endpoint is listed in WHITELIST_URLS, allowing unauthenticated access to the file upload API. While the server validates uploads based on the MIME types defined in chatbotConfig.fullFileUpload.allowedUploadFileTypes, it implicitly trusts the client-provided Content-Type header (file.mimetype) without verifying the file's actual content (magic bytes) or extension (file.originalname). Consequently, an attacker can bypass this restriction by spoofing the Content-Type as a permitted type (e.g., application/pdf) while uploading malicious scripts or arbitrary files. Once uploaded via addArrayFilesToStorage, these files persist in backend storage (S3, GCS, or local disk). This vulnerability serves as a critical entry point that, when chained with other features like static hosting or file retrieval, can lead to Stored XSS, malicious file hosting, or Remote Code Execution (RCE). This issue has been patched in version 3.0.13."}, {"lang": "es", "value": "Flowise es una interfaz de usuario de arrastrar y soltar para construir un flujo de modelo de lenguaje grande personalizado. Antes de la versi\u00f3n 3.0.13, el endpoint /api/v1/attachments/:chatflowId/:chatId est\u00e1 listado en WHITELIST_URLS, permitiendo acceso no autenticado a la API de carga de archivos. Aunque el servidor valida las cargas bas\u00e1ndose en los tipos MIME definidos en chatbotConfig.fullFileUpload.allowedUploadFileTypes, conf\u00eda impl\u00edcitamente en el encabezado Content-Type proporcionado por el cliente (file.mimetype) sin verificar el contenido real del archivo (bytes m\u00e1gicos) o la extensi\u00f3n (file.originalname). En consecuencia, un atacante puede eludir esta restricci\u00f3n falsificando el Content-Type como un tipo permitido (p. ej., application/pdf) mientras carga scripts maliciosos o archivos arbitrarios. Una vez cargados a trav\u00e9s de addArrayFilesToStorage, estos archivos persisten en el almacenamiento de backend (S3, GCS o disco local). Esta vulnerabilidad sirve como un punto de entrada cr\u00edtico que, cuando se encadena con otras caracter\u00edsticas como el alojamiento est\u00e1tico o la recuperaci\u00f3n de archivos, puede conducir a XSS Almacenado, alojamiento de archivos maliciosos o Ejecuci\u00f3n Remota de C\u00f3digo (RCE). Este problema ha sido parcheado en la versi\u00f3n 3.0.13."}], "lastModified": "2026-03-11T13:45:38.230", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:flowiseai:flowise:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8C6D6D18-106F-49FE-B523-B5DCAADFB40F", "versionEndExcluding": "3.0.13"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}