CVE-2026-49114

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{"affected": [{"affectedData": [{"defaultStatus": "unknown", "product": "ONNX", "vendor": "ONNX", "versions": [{"lessThan": "1.21.0", "status": "affected", "version": "0", "versionType": "custom"}, {"status": "unaffected", "version": "1.21.0"}]}], "source": "9119a7d8-5eab-497f-8521-727c672e3725"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:linuxfoundation:onnx:*:*:*:*:*:*:*:*", "matchCriteriaId": "D94F43D7-D50D-4698-B07D-215EBBAB63F2", "versionEndExcluding": "1.21.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In ONNX before 1.21.0, the 'save_external_data' function builds the external-data file path from the model's external_data location field and opens it for writing without 'O_NOFOLLOW/O_EXCL', after a non-atomic 'os.path.isfile()' check. A local attacker with write access to the directory where a victim serializes external data can deterministically pre-plant a symlink that is being followed, causing the victim's write to append to any file the victim can write, e.g. ~/.ssh/authorized_keys, cron files, or application configs. Fixed in 1.21.0."}, {"lang": "es", "value": "En ONNX antes de la versi\u00f3n 1.21.0, la funci\u00f3n 'save_external_data' construye la ruta del archivo de datos externos a partir del campo de ubicaci\u00f3n external_data del modelo y lo abre para escritura sin 'O_NOFOLLOW/O_EXCL', despu\u00e9s de una verificaci\u00f3n no at\u00f3mica de 'os.path.isfile()'. Un atacante local con acceso de escritura al directorio donde una v\u00edctima serializa datos externos puede pre-plantar de forma determinista un enlace simb\u00f3lico que se sigue, haciendo que la escritura de la v\u00edctima se a\u00f1ada a cualquier archivo que la v\u00edctima pueda escribir, por ejemplo, ~/.ssh/authorized_keys, archivos cron o configuraciones de aplicaciones. Corregido en la versi\u00f3n 1.21.0."}], "id": "CVE-2026-49114", "lastModified": "2026-10-15T19:10:00.173", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.2, "source": "9119a7d8-5eab-497f-8521-727c672e3725", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.8, "baseSeverity": "MEDIUM", "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": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "ACTIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "9119a7d8-5eab-497f-8521-727c672e3725", "type": "Secondary"}], "ssvcV203": [{"source": "9119a7d8-5eab-497f-8521-727c672e3725", "ssvcData": {"id": "CVE-2026-49114", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-05-27T16:00:11.944488Z", "version": "2.0.3"}}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-49114", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-21T16:42:42.598941Z", "version": "2.0.3"}}]}, "published": "2026-08-21T16:17:17.863", "references": [{"source": "9119a7d8-5eab-497f-8521-727c672e3725", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/onnx/onnx/security/advisories/GHSA-q56x-g2fj-4rj6"}, {"source": "9119a7d8-5eab-497f-8521-727c672e3725", "tags": ["VDB Entry"], "url": "https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-233-01.json"}, {"source": "9119a7d8-5eab-497f-8521-727c672e3725", "tags": ["Third Party Advisory", "VDB Entry"], "url": "https://www.cve.org/CVERecord?id=CVE-2026-49114"}], "sourceIdentifier": "9119a7d8-5eab-497f-8521-727c672e3725", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-22"}, {"lang": "en", "value": "CWE-59"}, {"lang": "en", "value": "CWE-367"}], "source": "9119a7d8-5eab-497f-8521-727c672e3725", "type": "Secondary"}]}

{"bugzilla": {"description": "onnx: ONNX: Arbitrary file write via symlink following and path traversal", "id": "2521048", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2521048"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.3", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-367", "details": ["In ONNX before 1.21.0, the 'save_external_data' function builds the external-data file path from the model's external_data location field and opens it for writing without 'O_NOFOLLOW/O_EXCL', after a non-atomic 'os.path.isfile()' check. A local attacker with write access to the directory where a victim serializes external data can deterministically pre-plant a symlink that is being followed, causing the victim's write to append to any file the victim can write, e.g. ~/.ssh/authorized_keys, cron files, or application configs. Fixed in 1.21.0.", "A flaw was found in ONNX. The `save_external_data` function is vulnerable to symlink following and path traversal. A local attacker with write access to a directory where a victim serializes external data can exploit this by pre-planting a symlink. This allows the attacker to cause the victim's write operation to append to arbitrary files, potentially leading to unauthorized modification of critical system files."], "name": "CVE-2026-49114", "public_date": "2026-08-21T16:10:56Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-49114\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-49114\nhttps://github.com/onnx/onnx/security/advisories/GHSA-q56x-g2fj-4rj6\nhttps://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-233-01.json"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.21.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "1.21.0"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "ONNX", "source": "cna", "vendor": "ONNX"}, "product": "onnx", "vendor": "onnx"}], "created": "2026-08-21T17:30:03.707458+00:00", "updated": "2026-08-21T17:45:03.933816+00:00", "vendors": ["onnx", "onnx$PRODUCT$onnx"]}