Independent review of the maintainer pass found the SVG sanitizer
(packages/core/src/figma/sanitizeSvg.ts, reused by media-use's own
port) was itself bypassable: an unquoted href/xlink:href survived,
inline style="..." attributes were never checked, and a href bound
through a renamed XML namespace prefix (xmlns:x=".../1999/xlink",
x:href=...) slipped past the literal "xlink:href" match.
Rewrote sanitizeSvg as a tag/attribute tokenizer instead of a set of
literal-spelling regexes: parse each tag's attributes in any quoting
form, resolve the local name after stripping any namespace prefix,
then drop by local name (any on* handler, any *href whose value is
not a #fragment or data:image/ embed, any style attribute containing
url(, @import, expression( or javascript:). Ported the fix into
media-use's svg-sanitize.mjs identically. Legitimate url(#id)
references on non-style attributes (clip-path, fill) are untouched.
Also adds a 10s AbortSignal.timeout to freezeUrl's fetch, matching
every other fetchMedia call in this package - it had a size cap but
no deadline.
New cases for all three bypasses in both sanitizeSvg.test.ts and the
parity corpus, each reproducibly failing against the prior head.
Miguel Angel Simon Sierra
a12a50fc45