CVE-2026-66012
Unauthenticated remote plugin install & RCE in SiYuan via Publish/mcp
Is CVE-2026-66012 being exploited?
Not confirmed. CVE-2026-66012 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.55% probability of exploitation in the next 30 days.
How severe is CVE-2026-66012?
CVE-2026-66012 is rated Critical with a CVSS score of 10.0. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-66012?
Yes. A fix has been recorded for CVE-2026-66012. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-66012 affect?
CVE-2026-66012 affects SiYuan < v3.7.2, SiYuan Publish (Conf.Publish.Enable=true & Conf.Publish.Auth.Enable=false), MCP kernel POST /mcp endpoint, Desktop client plugins (data/plugins/). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-66012?
Upgrade to v3.7.2, disable anonymous Publish, restrict access, rotate tokens
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote unauthenticated attacker can read tokens, read/write workspace files, install malicious plugin leading to persistent admin takeover/RCE on desktop clients.
Immediate action required
- affected< 3.7.2
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.