GHSA-56mp-4f3v-fgj2

SiYuan v3.6.5 and earlier versions contain a stored cross-site scripting (XSS) vulnerability in the Attribute View (database) asset cell renderer that escalates to remote code execution (RCE) in the Electron desktop client. This is a neighbor-bug of CVE-2026-44588: the fix for -44588 used escapeAriaLabel() (double-escapes <), but the AV asset renderers were left using the weaker escapeAttr() (escapes only quotes) or no escaping at all.

Vulnerability Details

The Electron renderer is configured with nodeIntegration: true and contextIsolation: false (app/electron/main.js:307), allowing any JavaScript executing in the renderer to directly access Node.js APIs including require('child_process').

Two XSS sinks exist.

Sink 1 (Direct Stored XSS - triggers on page load)

app/src/protyle/render/av/cell.ts:1008:

  text += `<span class="b3-chip av__celltext--url ariaLabel" aria-label="${escapeAttr(item.content)}" data-name="${escapeAttr(item.name)}"

data-url="${escapeAttr(item.content)}">${item.name || item.content}</span>`;

The >${item.name || item.content}</span> portion is raw user input with zero escaping.

app/src/protyle/render/av/blockAttr.ts:93 (even worse - completely unescaped):

  html += `<img loading="lazy" class="av__cellassetimg ariaLabel" aria-label="${item.content}" src="${getCompressURL(item.content)}">`;

Rendered via action.ts:860: cellElement.innerHTML = renderCell(...) results in immediate XSS on page load.

Sink 2 (Hover-triggered XSS via aria-label round-trip)

• Same lines emit aria-label="${escapeAttr(item.content)}" on .ariaLabel elements.
• escapeAttr() (util/escape.ts:14) escapes only " and ' — NOT < or >.
• popover.ts:33 global mouseover handler reads aria-label via getAttribute (which attribute-decodes entities).
• Line 144: showTooltip(decodeURIComponent(tip), ...) then tooltip.ts:41: messageElement.innerHTML = message results in XSS on hover....