Universal links open external apps when disallowed / in PBM

[janbrasna]

Steps to reproduce

(Have native YouTube app installed. Or adapt with any other universal link scenario for whatever native app you might have, e.g. Google, GitHub, Reddit, Amazon, Instagram or others… With external apps disallowed in settings, or using Private browsing: …)
Open mozilla.org, scroll to interviews, click on any outbound YouTube.com link.

Expected behavior

Navigates to the youtube.com video in the browser.

Actual behavior

Launches external YouTube app.

Device & build information

• Device: iPhone mini12, iOS 18.7.2
• Build version: v148.0 (68218)
• First seen version: recently; used to work before (~months(?) ago)

Notes

This has regressed a few times, and been last resolved last year; see also:

• Refactor FXIOS-9909 block external links behavior #26738
• 'Block Opening External Apps' doesn't work #21727
• Bugfix FXIOS-9909 [Content Sharing] Block open external apps #26341
• Private tab opens amazon links in the amazon app #6717
• Clicking on links that also have an external application whilst in Private tabs will open the application without asking the user first #8417
• Interaction Between Amazon Website on Firefox and Amazon App #19829
• Block Opening External Apps doesn‘t block external apps  #21006

Attachments:

ScreenRecording_03-04-2026.mp4

 

┆Issue is synchronized with this Jira Task

[data-sync-user]

➤ Nishant Bhasin commented:

Filippo Zazzeroni do you remember this bug and if you investigated this before?

cc Alexandru Farcasanu

[data-sync-user]

➤ Filippo Zazzeroni commented:

Hi Nishant Bhasin i remember i added a fix for this, i tested on iOS 26 and the settings works properly

[janbrasna]

Trying on iPadOS 26.2/3 there is one extra thing to note — the YouTube.com link opens in whatever is my default browser. On Firefox default it opens in Firefox, with Focus as default it opens in Focus, when Safari is set it opens in Safari. Going to record that and note nightly versions.

[FilippoZazzeroni]

Thanks very much @janbrasna i didn't see it was related to the context menu, i guess that uses a different path to open the link and thus it avoids the common navigation with the WebView where we do the actual blocking. cc @dicarobinho could you have a look to this ? let me know if you need any help, happy to jump on a call to solve it.

[janbrasna]

No sorry the context menu was only to demonstrate the outbound YouTube.com URL — it was not used to trigger the event. Here's a recording from iPadOS 26.3.1 with Focus as the default browser to demonstrate the weirdness even more, clicking the YT link in FxiOS actually switching to Focus:

ScreenRecording_03-05-2026.18-48-28.mp4

The same when using Safari as default (no YT app, store or anything, just the default browser):

ScreenRecording_03-05-2026.18-46-56.mp4

(I first encountered this on Feb 10 on this same device: https://mozilla.slack.com/archives/C05C9RET70F/p1770736446365129?thread_ts=1770724834.474139&cid=C05C9RET70F — not going to native app or app store, but opening in a default browser. 📱🏅… wonderful world of Universal Links :[ …)

This is just to demonstrate the system link handling is totally beyond controllable, so I can only confirm the other users' reports that even after the last year's fix there's no wonder still occurrences of this continuing to exhibit this way.