Nixpkgs security tracker

Login with GitHub

Details of issue NIXPKGS-2026-2281

NIXPKGS-2026-2281
published 3 hours ago
SiYuan before v3.7.2 Unauthenticated Administrator Takeover via MCP
Permalink CVE-2026-66012
10.0 CRITICAL
  • CVSS version (CVSS): 4.0
  • Attack Vector (AV): Network (N)
  • Attack Complexity (AC): Low (L)
  • Attack Requirement (AT): None (N)
  • Privileges Required (PR): None (N)
  • User Interaction (UI): None (N)
  • Vulnerable System Impact Confidentiality (VC): High (H)
  • Vulnerable System Impact Integrity (VI): High (H)
  • Vulnerable System Impact Availability (VA): High (H)
  • Subsequent System Impact Confidentiality (SC): High (H)
  • Subsequent System Impact Integrity (SI): High (H)
  • Subsequent System Impact Availability (SA): High (H)
  • Modified Attack Vector (MAV): Network (N)
  • Modified Attack Complexity (MAC): Low (L)
  • Modified Attack Requirement (MAT): None (N)
  • Modified Privileges Required (MPR): None (N)
  • Modified User Interaction (MUI): None (N)
  • Modified Vulnerable System Impact Confidentiality (MVC): High (H)
  • Modified Vulnerable System Impact Integrity (MVI): High (H)
  • Modified Vulnerable System Impact Availability (MVA): High (H)
  • Modified Subsequent System Impact Confidentiality (MSC): High (H)
  • Modified Subsequent System Impact Integrity (MSI): High (H)
  • Modified Subsequent System Impact Availability (MSA): High (H)
  • Safety (S): Not Defined (X)
  • Automatable (AU): Not Defined (X)
  • Recovery (R): Not Defined (X)
  • Value Density (V): Not Defined (X)
  • Vulnerability Response Effort (RE): Not Defined (X)
  • Provider Urgency (U): Not Defined (X)
  • Confidentiality Req. (CR): Not Defined (X)
  • Integrity Req. (IR): Not Defined (X)
  • Availability Req. (AR): Not Defined (X)
  • Exploit Maturity (E): Not Defined (X)
updated 3 hours ago by @LeSuisse Activity log
  • Created suggestion
  • @LeSuisse accepted
  • @LeSuisse published on GitHub
SiYuan before v3.7.2 Unauthenticated Administrator Takeover via MCP

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.

Affected products

siyuan
  • ==3.7.2
  • <3.7.2

Matching in nixpkgs

pkgs.siyuan

Privacy-first personal knowledge management system that supports complete offline usage, as well as end-to-end encrypted data sync

Package maintainers