Please can something be done about this error on a brand new site install:

[04-Dec-2025 07:20:05 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:20:05 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:21:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:21:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:21:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:21:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:22:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:22:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:22:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:22:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:23:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:23:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:23:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581
[04-Dec-2025 07:23:04 UTC] PHP Warning:  Undefined array key "HTTP_HOST" in /home/ourdomainapp/r877.ourdomain.app/wp-content/plugins/bbpress/includes/common/functions.php on line 1581

Would appreciate some feedback please

[@robin-w Moderator 1 day, 3 hours ago]

so when does this error occur?

[@pineapplepalm Participant 1 day, 2 hours ago]

Thank you for responding.

It’s happening constantly in our server domlogs. It’s a new site install. No active forum yet site isn’t launched yet. Seems to be happening simply from the site existing with bbpress on it.

I ran bbpress through Plugin Checker (WordPress official) and there are a lot of things that might be pinging this, not sure if the team are addressing performance, repo, general and the security issues raised in it?

Our environment

WP Core: 6.9
PHP: 8.4
Hosting: VPS
Theme: Reign (wbcomdesigns)
max_exec_time: 600

[@robin-w Moderator 11 hours, 12 minutes ago]

ok, thanks.

the line of code referred to is looking for a host url on logout from bbpress.

‘$redirect_to = bbp_get_url_scheme() . $_SERVER[‘HTTP_HOST’] . $_SERVER[‘REQUEST_URI’];’

$_SERVER is a php thing and the manual says ‘$_SERVER an array containing information such as headers, paths, and script locations. The entries in this array are created by the web server, therefore there is no guarantee that every web server will provide any of these; servers may omit some, or provide others not listed here. However, most of these variables are accounted for in the » CGI/1.1 specification, and are likely to be defined.’

Are you maybe running on a local host?

[@mike80222 Participant 3 hours, 55 minutes ago]

Just my two cents worth. I don’t actually understand this issue, but this crops up on all my sites on AWS Lightsail. I’ve had some success defining those PHP variables in wp-config.php, but it doesn’t always work. Searching on things like “http_host undefined” yields some interesting information which might help. I’m pretty sure that this is not actually specific to bbpress.

[@robin-w Moderator 3 hours, 51 minutes ago]

@mike80222 many thanks for this useful information 🙂 much appreciated