From 7531034769ac8e96336aa8b75f75ea9b2a23cc2c Mon Sep 17 00:00:00 2001
From: Alan Agius <17563226+alan-agius4@users.noreply.github.com>
Date: Thu, 26 Mar 2026 10:54:23 +0000
Subject: [PATCH] fix(@angular/ssr): allow underscores in host validation

The VALID_HOST_REGEX has been updated to include the underscore
character. This ensures that hostnames containing underscores (e.g., in
some internal or development environments) are correctly validated
instead of being rejected.

Closes #32835
---
 packages/angular/ssr/src/utils/validation.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/angular/ssr/src/utils/validation.ts b/packages/angular/ssr/src/utils/validation.ts
index e359b94aac6f..8c2d45aa4b9b 100644
--- a/packages/angular/ssr/src/utils/validation.ts
+++ b/packages/angular/ssr/src/utils/validation.ts
@@ -24,7 +24,7 @@ const VALID_PROTO_REGEX = /^https?$/i;
 /**
  * Regular expression to validate that the host is a valid hostname.
  */
-const VALID_HOST_REGEX = /^[a-z0-9.:-]+$/i;
+const VALID_HOST_REGEX = /^[a-z0-9_.-]+(:[0-9]+)?$/i;
 
 /**
  * Regular expression to validate that the prefix is valid.