Skip to content
Critical Authorization Vulnerability in SiYuan (CVE-2026-66012)

Critical Authorization Vulnerability in SiYuan (CVE-2026-66012)

First seen 26 Jul 2026, 11:03 UTC • •

Article Content

Browse articles
ThreatCluster AI
ThreatCluster •July 27, 2026 at 11:03 UTC
  • •CVE-2026-66012 is a critical vulnerability with a CVSS score of 10.
  • •Attackers can exploit the flaw to gain administrative access and execute arbitrary code.
  • •Users must upgrade to SiYuan v3.7.2 or later to mitigate the risk.

A critical missing authorization vulnerability (CVE-2026-66012) has been identified in SiYuan versions prior to 3.7.2, allowing remote unauthenticated attackers to bypass authentication on the POST /mcp kernel endpoint. This vulnerability exposes 31 MCP tools, including file management capabilities, and enables attackers to read sensitive configuration files and execute arbitrary code with administrative privileges. The flaw is particularly dangerous when the Publish server is enabled in anonymous mode, as it allows attackers to plant malicious plugins that execute on desktop launch. A CVSS base score of 10 has been assigned, indicating critical severity. Currently, there is no evidence of active exploitation or public proof-of-concept available. Users are advised to upgrade to version 3.7.2 or later and review their workspaces for unauthorized files. The vulnerability was first published on July 25, 2026.

Start a free Starter trial for enhanced analysis

Ask AI about this cluster

Updated 91d ago How this analysis works

Timeline

2026-07-25
CVE-2026-66012 published
Details of a critical missing authorization vulnerability in SiYuan were disclosed, affecting versions prior to 3.7.2.
Feedly
2026-07-26
INCIBE-CERT issues alert
INCIBE-CERT confirmed the critical nature of CVE-2026-66012, emphasizing the risk of administrator takeover.
www.incibe.es

More articles in this cluster (8)

Following this threat?

Track SiYuan and CVE-2026-66012 in your own feed — you're alerted when they show up in new reporting, leak sites or exploitation.

Free account · no card needed