431 (request headers too large) when user accesses own account #29202

GregJohnStewart · 2024-05-02T04:17:37Z

GregJohnStewart
May 2, 2024

Hello, I have the following flow:

User logs into my (quarkus based) app fine
User navigates to https://my-keycloak/realms/myrealm/account via a link on my app
Results in blank screen, firefox dev tools say the request is a 431. No logs in kc output

Interestingly this happened after I started running my keycloak instance with start instead of start-dev. I don't think it is a realm or permissions issue as such.

I'm imagining it could be from the large number of cookies that are sent with the request?

Any ideas?

Answered by GregJohnStewart

May 2, 2024

Found: #10236

Looks like QUARKUS_HTTP_HTTP2=false is still required in 24.0. I was able to get it working without QUARKUS_HTTP_LIMITS_MAX_HEADER_SIZE

View full answer

GregJohnStewart · 2024-05-02T04:55:34Z

GregJohnStewart
May 2, 2024
Author

Found: #10236

Looks like QUARKUS_HTTP_HTTP2=false is still required in 24.0. I was able to get it working without QUARKUS_HTTP_LIMITS_MAX_HEADER_SIZE

2 replies

codespearhead May 2, 2024

@GregJohnStewart Thanks for disclosing what worked for you and marking it as the answer, thereby closing the discussion.

While QUARKUS_HTTP_HTTP2=false works, it's more of a workaround than an actual solution in my opinion.

Can you try QUARKUS_HTTP_LIMITS_MAX_HEADER_SIZE=100k and tell us in this answer if that works for you? You can comment something along the lines of "I confirm QUARKUS_HTTP_LIMITS_MAX_HEADER_SIZE=100k works in Keycloak xx.x.x" and your testimony might help get that discussion closed as well.

Possible duplicates: #29162 , #10236 , #13933 .

aazaroual Aug 12, 2025

@codespearhead I had the same error in Keycloak 24.0.5 and I solved it by creating /opt/keycloak/24.0.5/conf/quarkus.properties and putting the following lines in it:

quarkus.http.limits.max-header-list-size=16384
quarkus.http.limits.max-header-size=100K

Restart Keycloak and now it works! BUT BE CAREFUL: BOTH LINES MUST BE THERE, IF YOU PUT ONLY ONE OF THOSE IT WON'T WORK!

Navigation Menu

Repository navigation

431 (request headers too large) when user accesses own account #29202

Uh oh!

{{title}}

Uh oh!

Uh oh!

{{editor}}'s edit

{{editor}}'s edit

Uh oh!

Replies: 1 comment 2 replies

Uh oh!

{{title}}

Uh oh!

Uh oh!

{{title}}

Uh oh!

Uh oh!

{{editor}}'s edit

{{editor}}'s edit

Uh oh!

Uh oh!

{{title}}

Uh oh!

Uh oh!

{{editor}}'s edit

{{editor}}'s edit

Uh oh!

Select a reply

Uh oh!

431 (request headers too large) when user accesses own account #29202

Uh oh!

Uh oh!

GregJohnStewart May 2, 2024

Replies: 1 comment · 2 replies

Uh oh!

GregJohnStewart May 2, 2024 Author

Uh oh!

Uh oh!

codespearhead May 2, 2024

Uh oh!

Uh oh!

aazaroual Aug 12, 2025

GregJohnStewart
May 2, 2024

Replies: 1 comment 2 replies

GregJohnStewart
May 2, 2024
Author