CVE intelligence and bounded remediation

CVE-2026-56395 — SiYuan security vulnerability

Critical CVSS 9.6

SiYuan before v3.6.1 fails to sanitize package metadata and README content in the Bazaar marketplace, allowing malicious package authors to inject arbitrary HTML and JavaScript. Attackers can achieve remote code execution on any user browsing the Bazaar by embedding XSS payloads in package displayName, description, or README fields, exploiting Electron's nodeIntegration setting to execute OS commands.

Severity
Critical
CVSS
9.6 (3.1)
Published
2026-06-21
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-79

Affected products

No browser-safe affected-product rows are available.

Matched remediation archetype

Cross-site scripting and unsafe browser output

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Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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