← WebKit Silent-Fix Report — 2026-W23

d58bad697e50a0bda1ff67669bb4cf9e1f78662e  [JSC] `ISO8601::parseDate` reads past the end of the buffer for short invalid strings

severity medium class OOB confidence 0.55 JSC Temporal ISO8601
Sosuke Suzuki Thu Jun 4 21:16:33 2026 -0700 full: d58bad697e50a0bda1ff67669bb4cf9e1f78662e bug report ↗ view on GitHub ↗
Primitive: Out-of-bounds read in ISO8601::parseDate for short truncated strings
Triage note: ISO8601::parseDate applied month/day length guards only to the full Date format, so short invalid Temporal strings (e.g. "12", "--1", "2024-0") read past the buffer end; fix adds length bounds so they throw RangeError, a web-reachable OOB read.

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…