nginx 1.17.9-1~bionic - 400 error

Maxim Dounin mdounin at
Thu Mar 5 13:21:11 UTC 2020


On Wed, Mar 04, 2020 at 08:54:49PM +0100, roland-brieden at wrote:

>    Hey Guys.
>    After todays update to nginx 1.17.9-1~bionic all my websites crashes
>    into 400 error.
>    Going back to nginx 1.17.8-1~bionic and all websites works ok.
>    What can i do?

First of all, check your error logs.  The reason for any 400 error 
returned by nginx is logged into error log at the "info" level.

Note though that the "info" level is below the default logging 
level, so you may need to adjust your configuration to see 
relevant errors.  See for details.

The most likely reason is that 400 errors you see are somehow 
related to duplicate Host or Transfer-Encoding, as outlined in 

    *) Change: now nginx does not allow several "Host" request header lines.

    *) Bugfix: nginx ignored additional "Transfer-Encoding" request header

Probably in your configuration requests with duplicate headers are 
generated somehow, leading to 400.

Just in case, relevant commits are:

Maxim Dounin

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