← WebKit Silent-Fix Report — 2026-W23

3825a1a93bbf70dba2406c75919f5d5049a18607  [JSC] Fix undefined behavior in double-to-int conversions

severity low class Other confidence 0.55 JSC runtime
Sosuke Suzuki Tue Jun 2 03:54:45 2026 -0700 full: 3825a1a93bbf70dba2406c75919f5d5049a18607 bug report ↗ view on GitHub ↗
Primitive: Undefined behavior in double-to-int conversion for property/array indices
Triage note: Fixes UB when converting out-of-uint32-range double subscripts (e.g. 4294967296, large JSONP array indices) to integer indices in property access; incorrect double-to-int conversion in index handling is a soundness bug though no direct OOB primitive is shown in the visible diff.

Security-relevant, below the exploitable-grade bar for a full root-cause writeup. The triage verdict is above; the side-by-side patch is below.

Before / after

Loading diff…