SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, he tooltip mouseover handler in app/src/block/popover.ts reads aria-label via getAttribute and passes it through decodeURIComponent before assigning to messageElement.innerHTML in app/src/dialog/tooltip.ts:41. The encoder used at the producer side, escapeAriaLabel in app/src/util/escape.ts:19-25, only handles HTML special characters (", ', <, literal <) — it leaves %XX URL-escapes untouched. So a doc title containing %3Cimg src=x onerror=...%3E round-trips through escapeAriaLabel and the HTML attribute layer unmodified. Then decodeURIComponent on the consumer side converts %3C to a literal < character (a real <, NOT a character reference). When that string is assigned to innerHTML, the HTML5 tokenizer enters TagOpenState on the literal <, parses the <img> element, and the onerror handler fires. Because the renderer runs with nodeIntegration: true, contextIsolation: false, webSecurity: false (app/electron/main.js:407-411), require('child_process') is reachable from the injected handler, escalating to arbitrary code execution.This vulnerability is fixed in 3.7.0.
Affected: Go: github.com/siyuan-note/siyuan/kernel
## Summary
The tooltip mouseover handler in `app/src/block/popover.ts` reads `aria-label` via `getAttribute` and passes it through `decodeURIComponent` before assigning to `messageElement.innerHTML` in `app/src/dialog/tooltip.ts:41`. The encoder used at the producer side, `escapeAriaLabel` in `app/src/util/escape.ts:19-25`, only handles HTML special characters (`"`, `'`, `<`, literal `<`) — it leaves `%XX` URL-escapes untouched. So a doc title containing `%3Cimg src=x onerror=...%3E` round-trips through `escapeAriaLabel` and the HTML attribute layer unmodified. Then `decodeURIComponent` on the consumer side converts `%3C` to a literal `<` character (a real `<`, NOT a character reference). When that string is assigned to `innerHTML`, the HTML5 tokenizer enters TagOpenState on the literal `<`, parses the `<img>` element, and the `onerror` handler fires.
Because the renderer runs with `nodeIntegration: true, contextIsolation: false, webSecurity: false` (`app/electron/main.js:407-411`), `require('child_process')` is reachable from the injected handler, escalating to arbitrary code execution.
Doc titles, AV column names + descriptions, AV select options, file-tree tooltips all reach this sink because they're rendered into `class="ariaLabel"` elements with `aria-label="${escapeAriaLabel(...)}"`. Doc title is the easiest plant — any user with create/rename access lands the payload, and the file survives `.sy.zip` round-trip without modification.
## Why a "double HTML-decode"…