CRITICAL CVSS 9.8
Published: 2026-03-20

CVE-2026-32767

b3log siyuan Security Advisory (CVE-2026-32767)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2026-32767?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-32767 impacting b3log siyuan. Evaluated with CVSS Base Score of 9.8 (CRITICAL).

Original NVD Description

Source: NIST NVD
SiYuan is a personal knowledge management system. Versions 3.6.0 and below contain an authorization bypass vulnerability in the /api/search/fullTextSearchBlock endpoint. When the method parameter is set to 2, the endpoint passes user-supplied input directly as a raw SQL statement to the underlying SQLite database without any authorization or read-only checks. This allows any authenticated user — including those with the Reader role — to execute arbitrary SQL statements (SELECT, DELETE, UPDATE, DROP TABLE, etc.) against the application's database. This is inconsistent with the application's own security model: the dedicated SQL endpoint (/api/query/sql) correctly requires both CheckAdminRole and CheckReadonly middleware, but the search endpoint bypasses these controls entirely. This issue has been fixed in version 3.6.1.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
High (C:H)
Total information disclosure
Integrity
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product b3log / siyuan
Affected Versions *
Weakness Enumeration CWE-89

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2026-32767 impacting b3log siyuan.

⚡ Nuclei Detection Template (YAML) cve-2026-32767.yaml
id: cve-2026-32767

info:
  name: b3log siyuan - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: critical
  description: |
    Automated signature & scanner for CVE-2026-32767 affecting b3log siyuan.
    Evaluation: SiYuan is a personal knowledge management system. Versions 3.6.0 and below contain an authorization bypass vulnerability in the /api/search/fullTextSe...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-32767
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2026-32767
    cwe-id: CWE-89
  tags: cve,cve-2026-32767,b3log,siyuan,critical

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "siyuan"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-32767.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-32767
# Target: b3log siyuan | CVSS: 9.8 (CRITICAL)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-32767 (b3log siyuan)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against b3log siyuan scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2026-32767.sh
# Recommended Remediation & Patching Commands for CVE-2026-32767
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install siyuan 2>/dev/null || \
sudo dnf upgrade siyuan 2>/dev/null || \
sudo yum update siyuan

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i siyuan 2>/dev/null || rpm -qa | grep -i siyuan

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-32767 in b3log siyuan?

Review vendor-specific security notices and update b3log siyuan packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2026-32767?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2026-32767?

CVE-2026-32767 is classified with a CVSS 3.1 Base Score of 9.8 (CRITICAL). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
9.8
CRITICAL SEVERITY
CVE ID CVE-2026-32767
Weakness CWE-89
Vendor b3log
Product siyuan
Published 2026-03-20
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H