«  Firefox 157 beta cycle 

Uplifts by Product
51 uplifts

  1. OOM | small (19.30%) Known top crash
  2. OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::AutoEnterOOMUnsafeRegion::crash | js::gc::AllocateTenuredCellInGC (9.93%) 1472062
  3. mozilla::dom::quota::QuotaManager::Shutdown::<T>::operator() (4.96%) 2069097
  4. shutdownhang | mozilla::SpinEventLoopUntil<T> | mozilla::dom::quota::QuotaManager::Observer::Observe (2.76%) 2069097
  5. AsyncShutdownTimeout | profile-before-change | Sqlite.sys.mjs shutdown blocker (2.02%) 2066466
  6. EMPTY: no frame data available; EmptyMinidump (2.02%) 1644486
  7. OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::AutoEnterOOMUnsafeRegion::crash | js::Nursery::maybeMoveRawBufferOnPromotion (1.84%)
Uplifts and Backouts
Bug Component Summary
2054193 Address Bar Add functionality to use form history to determine low/no SAP searchers
2056841 Storage: Quota Manager Crash in [@ mozilla::Maybe<T>::value | mozilla::dom::quota::OriginInfo::LockedTruncateUsages]
2057690 Search Configure Wikipedia search for Sardinian (sc) to use Sardinian wikipedia instead of Italian
2058886 UI Widgets [Linux][ScreenReader] No Focus while browsing light/dark/device and themes are read as "Blank"
2063718 Search Recent Searches Widget Core Functionality
2064563 Add-ons Manager about:addons themes mode control has no accessible name
2066084 Web Painting fix WPT css/css-transforms/backface-visibility-hidden-004.html
2066344 New Tab Page Add telemetry for theme selection in the New Tab customization panel
2067338 Web Painting misc cleanups to preserve3d wrapping display list code
2068046 UI Widgets [Nova] Avatar shadow is missing with the Default theme on macOS
2068505 Add-Ons: Extensions API Thunderbird 155: uBlock Origin cosmetic filters and element zapper no longer work in Full Web Page view
2068917 Themes Profiles menu low contrast items (name, icon and back arrow) with some official themes
2069127 Startup and Profile System Record theme-picker shown telemetry for Profiles
2069172 Themes Record appearance and native-theme changes from the theme picker
2069350 Sync Perma TEST-UNEXPECTED-FAIL | browser/base/content/test/sync/browser_contextmenu_sendtab.js | test_sendTabToDevice_showsConfirmationHint_onOverflowMenu - Uncaught exception in test when Gecko 157 merges to Beta on 2026-09-10
2069519 UI Widgets Record every theme-picker shown and change event
2069644 Security: Process Sandboxing Parent process leaks duplicated logon token handles (and correlated Event/Job/Process handles) during content process churn
2070194 Address Bar Newtab search icon is broken for extension search engines
2070206 Address Bar The input text added in the new tab search bar is placed in the left side on RTL builds
2070652 Machine Learning: Frontend Record Glean events for the Smart Window Firefox Accounts sign-in flow
2070834 Onboarding "How we use the data" link is missing from the onboarding marketing card
2070949 JavaScript Engine Crash in [@ js::irregexp::Execute]
2070982 General ./mach build fails with "[webpack-cli] TypeError: Cannot read properties of undefined (reading 'tap')"
2071073 Machine Learning: Frontend Smart Window pref-state metrics only report on the first metrics ping of each session
2068430 Other …
2068375 Other …
2050542 Other …
Uplifts and Backouts
Bug Component Summary
1976766 Graphics: WebGPU Calling `GPUDevice.destroy` while one of its buffers is being `GPUBuffer.mapAsync`'d causes a crash
2031836 Search Rename preferences related to a separate search engine in default private browsing mode
2062965 Machine Learning: Frontend The Organize tabs panels sees new Tabs with different conversations started as duplicated tabs
2063568 Machine Learning: Frontend The Organize tabs panel will suggest a Tab group with the same name as an already existing Tab group
2064041 Machine Learning: Frontend The organize tabs panel will not suggest any tab groups after the user restores the Smart window
2064054 Machine Learning: Frontend [Ubuntu] The sub-panel is overlapping the suggested groups
2070028 Frontend window.confirm does not work when used in WebExtension browser_action in Nightly 157
2070260 Sidebar Migrate old sidebar users to new switcher setting and enable sidebar.revamp in all builds
2070481 Site Reports berlin-brandenburg.dgb.de - The page-load animation is displayed incorrectly
2070562 Add-ons Manager Nova themes preview light/dark modes should be tied to the OS light/dark mode and not overridden as a side effect of about:settings Website appearance set to light/dark
2070622 Geolocation Provider Add telemetry to categorize the NetworkGeolocationProvider URL when used
2070675 Experimentation and Telemetry Use the Adjust dynamic callbacks partner for Skyflag attributed users
2070753 Security Put the host's tokens first in the search CTA's derived query
2070871 Geolocation Provider Repeated geolocation requests pile up network location provider fallbacks while the location portal never delivers a position
2070972 WebRTC: Audio/Video Permanent mda failures after worker upgrade, e.g. dom/media/test/test_multiple_mediastreamtracks.html | single tracking bug
2071106 Audio/Video: Playback PlayReady hardware DRM playback fails when the stream starts with unencrypted content
2071179 Theme 6.87% Heap Unclassified (Linux) regression on Mon September 7 2026
2071270 CSS Parsing and Computation [css-values-5] @container style query using var from attr() does not invalidate when number changes
2071475 Crash Reporting Fenix SentryService has inconsistent data controls
2071499 Widget: Gtk Crash in [@ gdk_x11_window_get_xid]
2054736 Other …
2071064 Other …
2063658 Other …
2062740 Other …