DNR rule taking effect in wrong context

[Ctrl-Alb]

Prerequisites

• This is NOT a YouTube, Facebook, Twitch or a shortener/hosting site report. These sites MUST be reported by clicking their respective links.
• I read and understand the policy about what is a valid filter issue.
• I verified that this issue is not a duplicate. (Use this button to find out.). Comment in the old issue threads even when they are closed or even if you have a different problem.
• I did not remove any of the default filter lists, or I have verified that the issue was not caused by removing any of the default lists.
• I did not enable additional filter lists, or I have verified that the issue still occurs without enabling additional filter lists.
• I do not have custom filters/rules, or I have verified that the issue still occurs without custom filters/rules.
• I have verified that the web browser's built-in content blocker/tracking protection, network wide/DNS blocking, or my VPN is not causing the issue.
• I have turned off all other extensions and the issue still persists. (exception "Firefox Multi-Account Containers").
• If this is about a breakage or detection, I have verified that it is caused by uBlock Origin and isn't a site or browser issue.
• I have verified that the browser I am using is up to date with no pending updates.
• I did not answer truthfully to ALL the above checkboxes.

URL(s) where the issue occurs.

https://www.ilpost.it/2025/08/01/pubblicita-instagram-2/

and, in general, websites with Twitter / X embedded posts

Description

Hello,
If I enable the EasyList – Social Widgets filter on uBOL in Safari, Twitter / x.com embedded posts are blocked.
Everything returns to normal if I disable the filter.
I tried enabling it on uBOL in Microsoft Edge on Windows 11, and the embedded posts are not blocked, so I suppose it’s a Safari-specific problem.
This problem on Safari occurs on both iOS (18.6.1) and macOS (15.6).

Browser name and version

Safari 18.6 (both on iOS and macOS)

Other extensions used

None

Country

No response

Screenshot(s)

Screenshot with `EasyList – Social Widgets` filter enabled

Screenshot with `EasyList – Social Widgets` filter disabled

Configuration

Details

name: uBlock Origin Lite
version: 2025.812.1339
browser: Safari Mobile 604 (ios)
filtering:
 site: basic
 default: basic
rulesets:
 adguard-spyware-url
 annoyances-others
 annoyances-social
 ublock-badware
 adguard-mobile
 annoyances-overlays
 ublock-filters
 block-lan
 annoyances-cookies
 annoyances-notifications
 annoyances-widgets
 ita-0
 pgl
 easylist
 easyprivacy

[gorhill]

While looking at another filter issue, I can see the same issue here:

https://www.breednet.com.au/news/41061/breeding-to-win-%E2%80%93-crystal-ball-%E2%80%93-new-season-3yos-to-follow

Embedded tweet in the article also doesn't render properly, just partially. Can't reproduce with Chromium.

[Ctrl-Alb]

Yes, I can confirm that the same problem occurs with the website you mentioned: on Safari, the embedded tweet doesn't load properly, while on Microsoft Edge it loads normally (both browsers with EasyList – Social Widgets filter enabled). Let me know if I can provide more information

[stephenhawk8054]

@gorhill I set the default filtering mode for all sites to "Basic", then turn off EasyList - Social Widgets and add only this filter from that list:

||platform.twitter.com/embed/$~stylesheet,~subdocument,third-party

then I can reproduce the issue.

In the Safari console I see

[Info] Content blocker prevented frame displaying https://www.ilpost.it/2025/08/01/pubblicita-instagram-2/ from loading a resource from https://platform.twitter.com/embed/embed.runtime.5c0ebab2383f6bc0454f.js
[Info] Content blocker prevented frame displaying https://www.ilpost.it/2025/08/01/pubblicita-instagram-2/ from loading a resource from https://platform.twitter.com/embed/embed.9449.78398904051446294e3d.js
[Info] Content blocker prevented frame displaying https://www.ilpost.it/2025/08/01/pubblicita-instagram-2/ from loading a resource from https://platform.twitter.com/embed/embed.Tweet.a2329252a62e74ea6e7d.js

Looks like Safari is understanding those scripts' origin is the website, not the twitter iframe?

[gorhill]

(Edit: Never mind, the official build the rule is fine.)

[gorhill]

In Develop editor, if I enter the following rule (without Social list enabled), I can reproduce:

action:
  type: block
condition:
  excludedInitiatorDomains:
    - twitter.com
  excludedResourceTypes:
    - main_frame
    - stylesheet
    - sub_frame
  urlFilter: ||platform.twitter.com/embed/

If instead I use the following rule, I cannot reproduce:

action:
  type: block
condition:
  excludedInitiatorDomains:
    - breednet.com.au
  excludedResourceTypes:
    - main_frame
    - stylesheet
    - sub_frame
  urlFilter: ||platform.twitter.com/embed/

Which confirms that the issue is with the Safari's DNR engine, it doesn't evaluate the current context correctly.

[gorhill]

I think we should badfilter that filter for the time being.

[stephenhawk8054]

Yeah, I agree. Also I think this should be moved to uBOL-home.