307121 2026-02-05 17:01:56 -0800 [Site Isolation] Back navigation fails when page contains iframe that navigated cross-site. 2026-02-13 12:09:58 -0800 1 1 1 Unclassified WebKit New Bugs WebKit Nightly Build Unspecified Unspecified REOPENED InRadar P2 Normal --- 307808 1 basuke basuke webkit-bug-importer oldest_to_newest 2178618 0 basuke 2026-02-05 17:01:56 -0800 When Site Isolation is enabled, back navigation incorrectly targets a cross-site iframe instead of the main frame when the iframe had previously navigated to a different site. Reproduction with Site Isolation enabled: 1. Load Page A (site A) with same-site iframe C (site A) 2. iframe navigates cross-site: C → D (site B) 3. Main frame navigates: Page A → Page B (same site with A) 4. Call goBack() Expected behavior: - goBack() should navigate the main frame back to Page A with page D in iframe Actual behavior: - page C is displayed in iframe 2178619 1 basuke 2026-02-05 17:03:44 -0800 rdar://169754535 2178666 2 basuke 2026-02-05 20:28:17 -0800 Pull request: https://github.com/WebKit/WebKit/pull/58023 2179470 3 ews-feeder 2026-02-09 09:25:48 -0800 Committed 307081@main (5fa8be5b7960): <https://commits.webkit.org/307081@main> Reviewed commits have been landed. Closing PR #58023 and removing active labels. 2181327 4 sihui_liu 2026-02-13 09:12:46 -0800 Reopened Bugzilla. Caused crash in PLT, tracking revert in https://bugs.webkit.org/show_bug.cgi?id=307808. 2181420 5 basuke 2026-02-13 12:09:58 -0800 Pull request: https://github.com/WebKit/WebKit/pull/58653