SiYuan before v3.7.2 Unauthenticated Administrator Takeover via MCP
CVSS score
10.0
EPSS probability
%0.8
Risk score
0.1
Published
2 mo ago
Etkilenen ürün ve sürüm için yayımlanan güvenlik güncellemesini uygulayın.
Impact on My Inventory
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Vulnerability description
DayBreach CVE AI Research
CVE-2026-66012 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.
SiYuan before v3.7.2 contains a missing authorization vulnerability in the POST /mcp kernel endpoint, which is gated only by a general auth check (model.CheckAuth) with no admin-role or read-only enforcement. This exposes 31 MCP tools, including a file tool with list/read/write/delete/rename/copy actions across the entire workspace. When the Publish server is enabled in anonymous mode (Conf.Publish.Enable=true and Conf.Publish.Auth.Enable=false), the Publish reverse proxy attaches an anonymous RoleReader JWT to proxied requests, allowing a remote unauthenticated attacker to reach /mcp. The attacker can read conf/conf.json to extract accessAuthCode, api.token, and cookieKey in plaintext, write arbitrary files in the workspace, and plant a plugin into data/plugins/ that executes with nodeIntegration:true and no contextIsolation on the next desktop launch, leading to administrator takeover.
IMPACT: Affected Products and Software
Affected Products
The following products are affected by CVE-2026-66012 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.
| ID | VENDOR | PRODUCT | ACTION |
|---|---|---|---|
| 1 | siyuan-note | siyuan | View |
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 10.0 | CVSS V31 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H | NVD |
| 10.0 | CVSS V40 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD |
| 10.0 | CVSS V4_0 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H | CVE CNA |
| 10.0 | CVSS V3_1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H | CVE CNA |
Patch and Remediation Guide
Solution & Remediation Advisory
2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.
https://github.com/siyuan-note/siyuan/commit/c72ca4cd09019e5f64afdee8f8c6ec5ef34858db
Open sourcehttps://github.com/siyuan-note/siyuan/commit/c72ca4cd09019e5f64afdee8f8c6ec5ef34858db
Open sourcePublic exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-66012 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-66012 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
CVSS Vector Radar Chart
10.0 / 10Vulnerability Scoring Details
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HYama doğrulandı
Weakness Type (CWE & CAPEC)
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Get this vulnerability through the API
Affected products, version ranges, exploitation status and patch information in a single request, with a free key.
curl -H "x-api-key: $DAYBREACH_API_KEY" \ "https://api.enginteksut.com.tr/api/v1/intel/cves/CVE-2026-66012"