diff --git a/test/Setup.Test/packages.lock.json b/test/Setup.Test/packages.lock.json
index f7f7b71ad4ac..37606942c260 100644
--- a/test/Setup.Test/packages.lock.json
+++ b/test/Setup.Test/packages.lock.json
@@ -1327,8 +1327,8 @@
       },
       "YamlDotNet": {
         "type": "Transitive",
-        "resolved": "11.2.1",
-        "contentHash": "tBt8K+korVfrjH9wyDEhiLKxbs8qoLCLIFwvYgkSUuMC9//w3z0cFQ8LQAI/5MCKq+BMil0cfRTRvPeE7eXhQw=="
+        "resolved": "18.0.0",
+        "contentHash": "ptHVgcYmLejGuWXV7RMFoEqFKYMXnieOlWLPzEslfDtzZ9ngMhjYwykfqjBN2+fMEAEyobozkj07lKEpR4dssA=="
       },
       "YubicoDotNetClient": {
         "type": "Transitive",
@@ -1431,7 +1431,7 @@
           "Handlebars.Net": "[2.1.6, 2.1.6]",
           "Microsoft.Extensions.Logging": "[10.0.8, 10.0.8]",
           "Migrator": "[2026.6.1, )",
-          "YamlDotNet": "[11.2.1, 11.2.1]"
+          "YamlDotNet": "[18.0.0, 18.0.0]"
         }
       }
     }
diff --git a/util/Setup/Setup.csproj b/util/Setup/Setup.csproj
index 447cad83c3aa..b844d2af4cdb 100644
--- a/util/Setup/Setup.csproj
+++ b/util/Setup/Setup.csproj
@@ -14,7 +14,7 @@
   <ItemGroup>
     <PackageReference Include="Handlebars.Net" Version="[2.1.6]" />
     <PackageReference Include="Microsoft.Extensions.Logging" Version="[10.0.8]" />
-    <PackageReference Include="YamlDotNet" Version="[11.2.1]" />
+    <PackageReference Include="YamlDotNet" Version="[18.0.0]" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/util/Setup/packages.lock.json b/util/Setup/packages.lock.json
index e0296d2f48f1..a073838c28a5 100644
--- a/util/Setup/packages.lock.json
+++ b/util/Setup/packages.lock.json
@@ -21,9 +21,9 @@
       },
       "YamlDotNet": {
         "type": "Direct",
-        "requested": "[11.2.1, 11.2.1]",
-        "resolved": "11.2.1",
-        "contentHash": "tBt8K+korVfrjH9wyDEhiLKxbs8qoLCLIFwvYgkSUuMC9//w3z0cFQ8LQAI/5MCKq+BMil0cfRTRvPeE7eXhQw=="
+        "requested": "[18.0.0, 18.0.0]",
+        "resolved": "18.0.0",
+        "contentHash": "ptHVgcYmLejGuWXV7RMFoEqFKYMXnieOlWLPzEslfDtzZ9ngMhjYwykfqjBN2+fMEAEyobozkj07lKEpR4dssA=="
       },
       "AdaptiveCards": {
         "type": "Transitive",