Add more details to the announcement

Author: gsmet

_posts/2025-08-29-quarkus-3-26-1-released.adoc

@@ -3,13 +3,19 @@ layout: post
 title: 'Quarkus 3.26.1, 3.20.2.2 and 3.15.6.2 - Emergency releases'
 date: 2025-08-29
 tags: release
-synopsis: 'We released Quarkus 3.26.1, 3.20.2.2 and 3.15.6.2 as emergency releases.'
+synopsis: 'We released Quarkus 3.26.1, 3.20.2.2 and 3.15.6.2 as emergency releases to address a Vert.x regression.'
 author: gsmet
 ---
 
 Today, we released Quarkus 3.26.1, 3.20.2.2 and 3.15.6.2 to fix an important regression introduced in Vert.x 4.5.18.
 
-We recommend upgrading to these releases as soon as possible if you are using a Quarkus version using Vert.x 4.5.18 (i.e. 3.26.0, 3.25.4, 3.20.2.1, and 3.15.6.1).
+A regression in Vert.x introduced in 4.5.18 can lead to a pool HTTP client connection that does not have a correct state and stop making progress when receiving bytes,
+so the application will not observe the entirety of the HTTP response and therefore hang when receiving the data.
+It also means that clients of the library might not obtain a connection in a timely manner.
+
+It has been https://github.com/eclipse-vertx/vert.x/pull/5683[fixed] in Vert.x 4.5.20 and we decided to push emergency releases for our current and LTS streams to promptly address the issue.
+
+We recommend upgrading to these releases without delay if you are using a Quarkus version based on Vert.x 4.5.18 (i.e. 3.26.0, 3.25.4, 3.20.2.1, and 3.15.6.1).
 
 Quarkus 3.26.1 also contains some other unrelated fixes.