apache · pjfanning · Jun 23, 2026 · Aug 24, 2026 · Aug 24, 2026 · Aug 24, 2026
diff --git a/.github/workflows/dependency-graph.yml b/.github/workflows/dependency-graph.yml
@@ -28,7 +28,7 @@ jobs:
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
       - uses: scalacenter/sbt-dependency-submission@f43202114d7522a4b233e052f82c2eea8d658134 # v3.2.1
         with:
           modules-ignore: pekko-http-tests_3 pekko-http-docs_3
diff --git a/.github/workflows/headers.yml b/.github/workflows/headers.yml
@@ -37,10 +37,10 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@90c37294538be80a558fd665531fcdc2b467b475 # v8.1.0
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Enable jvm-opts
         run: cp .jvmopts-ci .jvmopts

diff --git a/.github/workflows/link-validator.yml b/.github/workflows/link-validator.yml
@@ -38,10 +38,10 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@90c37294538be80a558fd665531fcdc2b467b475 # v8.1.0
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Setup Coursier
         uses: coursier/setup-action@fd1707a76b027efdfb66ca79318b4d29b72e5a02 # v3.0.0

diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
@@ -38,13 +38,13 @@ jobs:
           java-version: ${{ matrix.JDK }}
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@90c37294538be80a558fd665531fcdc2b467b475 # v8.1.0
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Cache Build Target
-        uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
           path: project/**/target
           key: build-target-${{ hashFiles('**/*.sbt', 'project/build.properties', 'project/**/*.scala') }}

diff --git a/.github/workflows/publish-1.0-docs.yml b/.github/workflows/publish-1.0-docs.yml
@@ -40,10 +40,10 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@90c37294538be80a558fd665531fcdc2b467b475 # v8.1.0
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Build Documentation
         run: |-

diff --git a/.github/workflows/publish-1.0-snapshots.yml b/.github/workflows/publish-1.0-snapshots.yml
@@ -33,10 +33,10 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@90c37294538be80a558fd665531fcdc2b467b475 # v8.1.0
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Install graphviz
         run: sudo apt-get install -y graphviz

diff --git a/.github/workflows/publish-1.1-docs.yml b/.github/workflows/publish-1.1-docs.yml
@@ -40,10 +40,10 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@90c37294538be80a558fd665531fcdc2b467b475 # v8.1.0
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Build Documentation
         run: |-

diff --git a/.github/workflows/publish-1.1-snapshots.yml b/.github/workflows/publish-1.1-snapshots.yml
@@ -33,10 +33,10 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@90c37294538be80a558fd665531fcdc2b467b475 # v8.1.0
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Install graphviz
         run: sudo apt-get install -y graphviz

diff --git a/.github/workflows/publish-1.2-docs.yml b/.github/workflows/publish-1.2-docs.yml
@@ -39,10 +39,10 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@v1
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@v6
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Build Documentation
         run: |-

diff --git a/.github/workflows/publish-1.3-docs.yml b/.github/workflows/publish-1.3-docs.yml
@@ -40,10 +40,10 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@6c68d2fe8dfbc0a0534d70101baa2e0420e1a506 # v1.1.9
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@v6
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Build Documentation
         run: |-

diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
@@ -41,10 +41,10 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@90c37294538be80a558fd665531fcdc2b467b475 # v8.1.0
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Install graphviz
         run: sudo apt-get install -y graphviz
@@ -74,10 +74,10 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@90c37294538be80a558fd665531fcdc2b467b475 # v8.1.0
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Build Documentation
         run: |-

diff --git a/.github/workflows/stage-release-candidate.yml b/.github/workflows/stage-release-candidate.yml
@@ -212,7 +212,7 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Install Graphviz
         run: |-

diff --git a/.github/workflows/validate-and-test.yml b/.github/workflows/validate-and-test.yml
@@ -38,13 +38,13 @@ jobs:
           java-version: 8
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@90c37294538be80a558fd665531fcdc2b467b475 # v8.1.0
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Cache Build Target
-        uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
           path: project/**/target
           key: build-target-${{ hashFiles('**/*.sbt', 'project/build.properties', 'project/**/*.scala') }}
@@ -86,13 +86,13 @@ jobs:
           java-version: ${{ matrix.JDK }}
 
       - name: Install sbt
-        uses: sbt/setup-sbt@66fb4376e81982c7d92a4074170846fff88e2e30 # v1.5.0
+        uses: sbt/setup-sbt@8feba82adc7f01ddcf8165b86f778bdb5b82cebc # v1.5.7
 
       - name: Cache Coursier cache
-        uses: coursier/cache-action@90c37294538be80a558fd665531fcdc2b467b475 # v8.1.0
+        uses: coursier/cache-action@95e5b1029b6b86e7bac033ee44a0697d8a527d2d # v8.1.1
 
       - name: Cache Build Target
-        uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
           path: project/**/target
           key: build-target-${{ hashFiles('**/*.sbt', 'project/build.properties', 'project/**/*.scala') }}

diff --git a/http-core/src/main/scala/org/apache/pekko/http/impl/engine/http2/Http2Blueprint.scala b/http-core/src/main/scala/org/apache/pekko/http/impl/engine/http2/Http2Blueprint.scala
@@ -38,8 +38,8 @@ import pekko.http.scaladsl.settings.{
 import pekko.stream.{ BidiShape, Graph, StreamTcpException, ThrottleMode }
 import pekko.stream.TLSProtocol._
 import pekko.stream.scaladsl.{ BidiFlow, Flow, Keep, Source }
-import pekko.util.ByteString
-import pekko.util.OptionVal
+import pekko.util.{ ByteString, OptionVal }
+import pekko.util.Helpers.toRootLowerCase
 
 import scala.concurrent.duration.{ Duration, FiniteDuration }
 import scala.concurrent.{ ExecutionContext, Future }
@@ -226,7 +226,7 @@ private[http] object Http2Blueprint {
   }
 
   private[http2] def frameTypeAliasToFrameTypeName(frameType: String): Option[String] = {
-    frameType.toLowerCase match {
+    toRootLowerCase(frameType) match {
       case "reset"         => Some("RstStreamFrame")
       case "headers"       => Some("HeadersFrame")
       case "continuation"  => Some("ContinuationFrame")

diff --git a/http-core/src/main/scala/org/apache/pekko/http/impl/settings/ParserSettingsImpl.scala b/http-core/src/main/scala/org/apache/pekko/http/impl/settings/ParserSettingsImpl.scala
@@ -23,6 +23,7 @@ import pekko.http.scaladsl.settings.ParserSettings.{
   IllegalResponseHeaderValueProcessingMode
 }
 import pekko.util.ConstantFun
+import pekko.util.Helpers.toRootLowerCase
 import com.typesafe.config.Config
 
 import scala.collection.JavaConverters._
@@ -115,7 +116,7 @@ object ParserSettingsImpl extends SettingsCompanionImpl[ParserSettingsImpl]("pek
       Uri.ParsingMode(c.getString("uri-parsing-mode")),
       CookieParsingMode(c.getString("cookie-parsing-mode")),
       c.getBoolean("illegal-header-warnings"),
-      c.getStringList("ignore-illegal-header-for").asScala.map(_.toLowerCase).toSet,
+      c.getStringList("ignore-illegal-header-for").asScala.map(toRootLowerCase).toSet,
       ErrorLoggingVerbosity(c.getString("error-logging-verbosity")),
       IllegalResponseHeaderNameProcessingMode(c.getString("illegal-response-header-name-processing-mode")),
       IllegalResponseHeaderValueProcessingMode(c.getString("illegal-response-header-value-processing-mode")),

diff --git a/http-core/src/main/scala/org/apache/pekko/http/javadsl/ConnectHttp.scala b/http-core/src/main/scala/org/apache/pekko/http/javadsl/ConnectHttp.scala
@@ -13,12 +13,12 @@
 
 package org.apache.pekko.http.javadsl
 
-import java.util.Locale
 import java.util.Optional
 
 import org.apache.pekko
 import pekko.annotation.{ DoNotInherit, InternalApi }
 import pekko.http.javadsl.model.Uri
+import pekko.util.Helpers.toRootLowerCase
 import pekko.util.OptionConverters._
 
 @DoNotInherit
@@ -71,7 +71,7 @@ object ConnectHttp {
   }
 
   private def toHost(uriHost: Uri, port: Int): ConnectHttp = {
-    val s = uriHost.scheme.toLowerCase(Locale.ROOT)
+    val s = toRootLowerCase(uriHost.scheme)
     if (s == "https") new ConnectHttpsImpl(uriHost.host.address, effectivePort(s, port), context = Optional.empty())
     else new ConnectHttpImpl(uriHost.host.address, effectivePort(s, port))
   }
@@ -114,7 +114,7 @@ object ConnectHttp {
   }
 
   private def toHostHttps(uriHost: Uri, port: Int): ConnectWithHttps = {
-    val s = uriHost.scheme.toLowerCase(Locale.ROOT)
+    val s = toRootLowerCase(uriHost.scheme)
     require(s == "" || s == "https", "toHostHttps used with non https scheme! Was: " + uriHost)
     new ConnectHttpsImpl(uriHost.host.address, effectivePort("https", port), context = Optional.empty())
   }
@@ -125,7 +125,7 @@ object ConnectHttp {
   }
 
   private def effectivePort(scheme: String, port: Int): Int = {
-    val s = scheme.toLowerCase(Locale.ROOT)
+    val s = toRootLowerCase(scheme)
     if (port >= 0) port
     else if (s == "https" || s == "wss") 443
     else if (s == "http" || s == "ws") 80

diff --git a/http-core/src/main/scala/org/apache/pekko/http/javadsl/settings/ParserSettings.scala b/http-core/src/main/scala/org/apache/pekko/http/javadsl/settings/ParserSettings.scala
@@ -23,6 +23,7 @@ import java.{ util => ju }
 
 import pekko.annotation.DoNotInherit
 import pekko.http.impl.util.JavaMapping.Implicits._
+import pekko.util.Helpers.toRootLowerCase
 
 import scala.annotation.varargs
 import scala.collection.JavaConverters._
@@ -90,7 +91,7 @@ abstract class ParserSettings private[pekko] () extends BodyPartParser.Settings
     self.copy(includeSslSessionAttribute = newValue)
   def withModeledHeaderParsing(newValue: Boolean): ParserSettings = self.copy(modeledHeaderParsing = newValue)
   def withIgnoreIllegalHeaderFor(newValue: List[String]): ParserSettings =
-    self.copy(ignoreIllegalHeaderFor = newValue.map(_.toLowerCase).toSet)
+    self.copy(ignoreIllegalHeaderFor = newValue.map(toRootLowerCase).toSet)
 
   // special ---
 

diff --git a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/ErrorInfo.scala b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/ErrorInfo.scala
@@ -14,7 +14,9 @@
 package org.apache.pekko.http.scaladsl.model
 
 import StatusCodes.ClientError
-import org.apache.pekko.annotation.InternalApi
+import org.apache.pekko
+import pekko.annotation.InternalApi
+import pekko.util.Helpers.toRootLowerCase
 
 /**
  * Two-level model of error information.
@@ -28,7 +30,7 @@ final class ErrorInfo(
     val errorHeaderName: String = "") extends scala.Product with scala.Equals with java.io.Serializable {
   def withSummary(newSummary: String) = copy(summary = newSummary)
   def withSummaryPrepended(prefix: String) = withSummary(if (summary.isEmpty) prefix else prefix + ": " + summary)
-  def withErrorHeaderName(headerName: String) = new ErrorInfo(summary, detail, headerName.toLowerCase)
+  def withErrorHeaderName(headerName: String) = new ErrorInfo(summary, detail, toRootLowerCase(headerName))
   def withFallbackSummary(fallbackSummary: String) = if (summary.isEmpty) withSummary(fallbackSummary) else this
   def formatPretty = if (summary.isEmpty) detail else if (detail.isEmpty) summary else summary + ": " + detail
   def format(withDetail: Boolean): String = if (withDetail) formatPretty else summary

diff --git a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/HttpHeader.scala b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/HttpHeader.scala
@@ -23,6 +23,7 @@ import pekko.http.impl.model.parser.{ CharacterClasses, HeaderParser }
 import pekko.http.javadsl.{ model => jm }
 import pekko.http.scaladsl.model.headers._
 import pekko.util.OptionVal
+import pekko.util.Helpers.toRootLowerCase
 
 import scala.collection.immutable
 
@@ -91,7 +92,7 @@ object HttpHeader {
       val parser = new HeaderParser(value, settings)
       parser.`header-field-value`.run() match {
         case Success(preProcessedValue) =>
-          HeaderParser.parseFull(name.toLowerCase, preProcessedValue, settings) match {
+          HeaderParser.parseFull(toRootLowerCase(name), preProcessedValue, settings) match {
             case HeaderParser.Success(header) => ParsingResult.Ok(header, Nil)
             case HeaderParser.Failure(info) =>
               val errors = info.withSummaryPrepended(s"Illegal HTTP header '$name'") :: Nil

diff --git a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/MediaType.scala b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/MediaType.scala
@@ -18,6 +18,7 @@ import pekko.annotation.DoNotInherit
 import pekko.http.impl.util._
 import pekko.http.javadsl.{ model => jm }
 import pekko.http.impl.util.JavaMapping.Implicits._
+import pekko.util.Helpers.toRootLowerCase
 
 /**
  * A MediaType describes the type of the content of an HTTP message entity.
@@ -74,7 +75,7 @@ sealed abstract class MediaType(_mainType: String, _subType: String) extends jm.
       case _            => false
     }
 
-  override def hashCode(): Int = value.toLowerCase.hashCode
+  override def hashCode(): Int = toRootLowerCase(value).hashCode
 
   /**
    * JAVA API
@@ -327,12 +328,12 @@ object MediaTypes extends ObjectRegistry[(String, String), MediaType] {
 
   private[this] var extensionMap = Map.empty[String, MediaType]
 
-  def forExtensionOption(ext: String): Option[MediaType] = extensionMap.get(ext.toLowerCase)
-  def forExtension(ext: String): MediaType = extensionMap.getOrElse(ext.toLowerCase, `application/octet-stream`)
+  def forExtensionOption(ext: String): Option[MediaType] = extensionMap.get(toRootLowerCase(ext))
+  def forExtension(ext: String): MediaType = extensionMap.getOrElse(toRootLowerCase(ext), `application/octet-stream`)
 
   private def registerFileExtensions[T <: MediaType](mediaType: T): T = {
     mediaType.fileExtensions.foreach { ext =>
-      val lcExt = ext.toLowerCase
+      val lcExt = toRootLowerCase(ext)
       require(!extensionMap.contains(lcExt),
         s"Extension '$ext' clash: media-types '${extensionMap(lcExt)}' and '$mediaType'")
       extensionMap = extensionMap.updated(lcExt, mediaType)

diff --git a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/Uri.scala b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/Uri.scala
@@ -28,6 +28,7 @@ import pekko.http.javadsl.{ model => jm }
 import pekko.http.impl.model.parser.UriParser
 import pekko.http.impl.model.parser.CharacterClasses._
 import pekko.http.impl.util._
+import pekko.util.Helpers.toRootLowerCase
 import Uri._
 
 /**
@@ -868,7 +869,7 @@ object Uri {
       } else if (allLower) -1
       else -2
     verify() match {
-      case -2 => scheme.toLowerCase
+      case -2 => toRootLowerCase(scheme)
       case -1 => scheme
       case ix => fail(s"Invalid URI scheme, unexpected character at pos $ix ('${scheme.charAt(ix)}')")
     }

diff --git a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/settings/ParserSettings.scala b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/settings/ParserSettings.scala
@@ -25,6 +25,7 @@ import pekko.http.impl.util._
 import pekko.http.javadsl.model
 import pekko.http.scaladsl.model._
 import pekko.http.scaladsl.{ settings => js }
+import pekko.util.Helpers.toRootLowerCase
 import pekko.util.OptionConverters._
 import com.typesafe.config.Config
 
@@ -123,7 +124,7 @@ abstract class ParserSettings private[pekko] () extends pekko.http.javadsl.setti
     self.copy(includeSslSessionAttribute = newValue)
   override def withModeledHeaderParsing(newValue: Boolean): ParserSettings = self.copy(modeledHeaderParsing = newValue)
   override def withIgnoreIllegalHeaderFor(newValue: List[String]): ParserSettings =
-    self.copy(ignoreIllegalHeaderFor = newValue.map(_.toLowerCase).toSet)
+    self.copy(ignoreIllegalHeaderFor = newValue.map(toRootLowerCase).toSet)
 
   // overloads for idiomatic Scala use
   def withUriParsingMode(newValue: Uri.ParsingMode): ParserSettings = self.copy(uriParsingMode = newValue)