Files
hyperframes/packages/core/src
Miguel Angel Simon Sierra 502d8d6cd9 fix(media-use): make the sanitizer's CSS scans linear on hostile input
The url() check used /url\(\s*(['"]?)([^)]*)\1\s*\)/ and the function
check /([-\w]*)\(/: on attacker padding these backtracked cubically and
quadratically (an unclosed url( plus 4,000 spaces took 20s; an 80,000
character word took 7.7s), and freeze runs the sanitizer synchronously on
bodies up to 256MB. Both are now single-pass indexOf scans (a million
characters in under 15ms), with the same verdict on ordinary input. A url()
value holding "(" is rejected, so a nested url( can't hide inside one.
A size test holds both payloads under 2s.
2026-09-23 07:38:38 -04:00
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