CVE-2026-40518

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Los atacantes pueden proporcionar valores de estilo de salto de ruta o rutas absolutas como nombre del agente para influir en la creaci\u00f3n de directorios y escribir archivos fuera del directorio de agentes personalizados previsto, logrando potencialmente la escritura arbitraria de archivos en el sistema sujeta a los permisos del sistema de archivos."}], "id": "CVE-2026-40518", "lastModified": "2026-10-26T21:10:00.170", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 4.2, "source": "disclosure@vulncheck.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.1, "baseSeverity": "CRITICAL", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.2, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 7.1, "baseSeverity": "HIGH", "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": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/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", "version": "4.0", "vulnAvailabilityImpact": "LOW", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-40518", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-04-17T18:35:29.825676Z", "version": "2.0.3"}}]}, "published": "2026-04-17T17:17:09.543", "references": [{"source": "disclosure@vulncheck.com", "tags": ["Patch"], "url": "https://github.com/bytedance/deer-flow/commit/2176b2bbfccfce25ceee08318813f96d843a13fd"}, {"source": "disclosure@vulncheck.com", "tags": ["Issue Tracking", "Patch"], "url": "https://github.com/bytedance/deer-flow/pull/2274"}, {"source": "disclosure@vulncheck.com", "tags": ["Third Party Advisory"], "url": "https://www.vulncheck.com/advisories/bytedance-deerflow-path-traversal-and-arbitrary-file-write-via-bootstrap-mode"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-22"}], "source": "disclosure@vulncheck.com", "type": "Secondary"}]}

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{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[0,2176b2bbfccfce25ceee08318813f96d843a13fd)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "deer-flow", "source": "cna", "vendor": "bytedance"}, "product": "deer-flow", "vendor": "bytedance"}], "analysis": {"en": {"generated_at": "2026-04-18T17:12:16.611285+00:00", "value": {"mitigation_remediation": ["Apply the code change in commit 2176b2b or later to enforce proper validation of agent names.", "If upgrading immediately is not possible, restrict access to bootstrap\u2011mode and enforce the least\u2011privilege principle on the file system directories used by DeerFlow so that the application cannot write outside the intended location.", "Implement validation or a whitelist for agent names to prevent traversal characters before the agent is created."], "summary": {"action": "Apply Patch", "impact": "Arbitrary File Write"}, "threat_synthesis": {"affected_systems": "ByteDance DeerFlow before commit\u00a02176b2b of the source repository is affected. The vulnerability applies to any deployment that uses the bootstrap\u2011mode custom\u2011agent creation before the code change that enforces proper validation.", "description_and_impact": "ByteDance DeerFlow contains a path traversal vulnerability in bootstrap\u2011mode custom\u2011agent creation. When creating an agent, the agent name is used without proper validation, allowing attackers to supply traversal sequences or absolute paths. This causes the application to create directories and write files outside the intended custom\u2011agent directory. Depending on the file type and the underlying filesystem permissions, the attacker could overwrite configuration files, place malicious binaries, or otherwise tamper with system state, potentially leading to arbitrary code execution or other privilege escalation.", "risk_and_exploitability": "The CVSS score of 7.1 classifies the issue as a Medium severity vulnerability. EPSS data is not available, and the vulnerability is not listed in CISA KEV. The likely attack vector is via bootstrap\u2011mode access, which may be provided through a web API or management interface; exploitation requires the attacker to have the ability to submit agent creation requests. If the underlying file system permissions grant write access to the attacker\u2019s user, the vulnerability could be used to modify or create arbitrary files, potentially enabling further attacks such as privilege escalation or remote code execution."}}}}, "created": "2026-04-17T20:35:12.003255+00:00", "updated": "2026-04-18T17:15:05.785915+00:00", "vendors": ["bytedance", "bytedance$PRODUCT$deer-flow"]}