Chromium 156 (host upgrade 2026-11-03) checks script-src-attr when an
inline handler attribute is created, in a document with no window as well
(WPT PR 62762; the follow-up PR 64290 that skips windowless documents is
not in 156). prosemirror-view's readHTML parses pasted HTML into the body
of a new createHTMLDocument, so the paste test at :154 got one report per
pasted handler (img onerror, a onclick, a onmouseover, svg onload), each
at editor.js:8212 with the document as target. No pasted handler reaches
the live document; Chromium 153, 151 and Brave 154 report nothing there.
The page record now sets aside only a script-src-attr report whose event
names editor.js at that readHTML line and whose target is the document.
The line is found from the bundle's text, and the lines that make the
parse target a new createHTMLDocument body are pinned; the test file
refuses to load if they change. h.quiet(), inert(), injected, errors and
rejections are unchanged. No product or CSP change.
New test: after a hostile paste, three live handlers each still fail
h.quiet() with one script-src-attr report: an onclick set on an editor
paragraph and clicked, an img onerror parsed into a page-owned detached
element, and an onclick prosemirror-view sets through its attributes prop
(a report naming editor.js at another line).
jason.woltje
0c6aa1a1e2