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SiYuan before v3.8.4 Cross-Site Scripting via Kramdown IAL

Type: advisorySource: Official CVE List1 source record

SiYuan v3.8.3 fails to HTML-escape the data-subtype attribute when generating gutter-button markup (app/src/protyle/gutter/button.ts, assigned via innerHTML in app/src/protyle/gutter/index.ts) from content pasted as plain-text Markdown containing a Kramdown inline attribute list (IAL). Because the shared Lute renderer parses Kramdown IAL from text/plain input, an attacker-supplied Markdown snippet using entity-encoded quotes in data-subtype breaks out of the attribute value when the gutter markup is re-parsed by the browser, injecting additional attributes such as autofocus and onfocus. If a victim pastes the crafted Markdown and the affected gutter control receives focus, the injected handler executes; in the Electron desktop application, where the main BrowserWindow enables Node integration and disables context isolation, this results in JavaScript execution with renderer Node.js privileges (remote code execution). Fixed in v3.8.4.

Announced Source revision 1
Original source ↗

CVE-2026-100639

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-100639

siyuan

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "vendor": "siyuan-note",
    "product": "siyuan",
    "versions": [
      {
        "status": "affected",
        "version": "0",
        "lessThan": "3.8.4",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "3.8.4",
        "versionType": "semver"
      }
    ],
    "defaultStatus": "unaffected"
  }
]
Related CVEs
CVE-2026-100639

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#3311 · Revision 1
Added to Heist Feed
Publisher date
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