Post slugs are appending '%ef%bf%bc' causing redirection errors

[danielcho]

We are noticing that certain articles on our site are getting this '%ef%bf%bc' string attached to the end of the post_name/slug, and causing a redirect error. On the front end sometimes the actual string shows up but other times it's just a blank in the url.
If we strip the post_names of this string of characters in the database, it seems to fix the issue, but nothing we are doing on our end seems to be appending them. A quick google search seems to give me the indication that it's related a copy paste error of some sort, but I personally wasn't able to replicate it on my own, though we have dozens of examples of it happening on our site in the past few months.

Examples:
​https://www.hercampus.com/school/sjsu/a-peek-into-the-education-system%ef%bf%bc
​https://www.hercampus.com/school/york-u/what-does-your-favorite-hozier-song-say-about-you%ef%bf%bc
​https://www.hercampus.com/school/psu/be-kind-to-your-retail-workers-on-black-friday%ef%bf%bc%ef%bf%bc%ef%bf%bc%ef%bf%bc%ef%bf%bc%ef%bf%bc%ef%bf%bc%ef%bf%bc%ef%bf%bc
​https://www.hercampus.com/school/psu/what-new-fall-jacket-you-should-buy-based-on-your-favorite-thanksgiving-food%ef%bf%bc

[SergeyBiryukov]

Hi there, welcome back to WordPress Trac! Thanks for the report.

This should be fixed in WordPress 6.1 for new posts, the sanitize_title_with_dashes() function was updated to strip the object replacement character (%ef%bf%bc) from post slugs, see [54474] / #55117.

Does it still happen for new posts on a clean install?

[sajib1223]

Reproduction Report

Description

This report validates whether the issue can be reproduced.

Environment

• WordPress: 6.9
• PHP: 7.4.33
• Server: nginx/1.27.5
• Database: mysqli (Server: 8.0.33 / Client: mysqlnd 7.4.33)
• Browser: Firefox 145.0
• OS: Windows 10/11
• Theme: Astra 4.11.12
• MU Plugins:
  • Object Cache Pro (MU) 1.19.0
• Plugins:
  • Test Reports 1.2.1
  • WordPress Beta Tester 4.0.0
  • WP Crontrol 1.19.3

Actual Results

1. ❌ Error condition did not occurs.

Additional Notes

• I created several posts with the %ef%bf%bc (object replacement) character in the title.
• None of the generated slugs include this character.
• No redirection issues occurred.

Supplemental Artifacts

None.

[SirLouen]

Thanks @sajib1223

Since no one has been able to reproduce this and more than 3 years have passed since last comment from @SergeyBiryukov , it's time to close this as worksforme

@danielcho feel free to comment if you can provide additional information on how to reproduce this, and I will be happy to reopen and test it accordingly.