diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index b7b51cc0a..1ec5c34b1 100644
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -3550,7 +3550,13 @@ object Classpaths {
           classifiersModule := Def.uncached(classifiersModuleTask.value),
           // Redefine scalaVersion and scalaBinaryVersion specifically for the dependency graph used for updateSbtClassifiers task.
           // to fix https://github.com/sbt/sbt/issues/2686
-          scalaVersion := appConfiguration.value.provider.scalaProvider.version,
+          // For sbt plugins, use the Scala version corresponding to the sbt binary version being targeted.
+          // to fix https://github.com/sbt/sbt/issues/8026
+          scalaVersion := {
+            val isPlugin = sbtPlugin.value
+            if (isPlugin) (pluginCrossBuild / scalaVersion).value
+            else appConfiguration.value.provider.scalaProvider.version
+          },
           scalaBinaryVersion := binaryScalaVersion(scalaVersion.value),
           scalaEarlyVersion := CrossVersion.earlyScalaVersion(scalaVersion.value),
           scalaOrganization := ScalaArtifacts.Organization,
diff --git a/sbt-app/src/sbt-test/dependency-management/i8026-update-sbt-classifiers-cross-plugin/build.sbt b/sbt-app/src/sbt-test/dependency-management/i8026-update-sbt-classifiers-cross-plugin/build.sbt
new file mode 100644
index 000000000..6c097accc
--- /dev/null
+++ b/sbt-app/src/sbt-test/dependency-management/i8026-update-sbt-classifiers-cross-plugin/build.sbt
@@ -0,0 +1,18 @@
+// Test for https://github.com/sbt/sbt/issues/8026
+// When building sbt plugins with explicit scalaVersion set,
+// updateSbtClassifiers should use the correct Scala version for the sbt version.
+
+lazy val root = (project in file("."))
+  .enablePlugins(SbtPlugin)
+  .settings(
+    name := "test-sbt-cross-build",
+
+    // Explicitly set scala version - this is what caused the issue in #8026
+    // When scalaVersion is explicitly set, updateSbtClassifiers was using the
+    // launcher's Scala version instead of the plugin's Scala version.
+    // Before the fix, this would fail with:
+    //   Error downloading org.scala-sbt:scripted-plugin_2.12:0.13.17
+    // because it used the launcher's Scala version (2.12) instead of the
+    // plugin's target Scala version derived from sbt binary version.
+    scalaVersion := "2.12.21",
+  )
diff --git a/sbt-app/src/sbt-test/dependency-management/i8026-update-sbt-classifiers-cross-plugin/project/build.sbt b/sbt-app/src/sbt-test/dependency-management/i8026-update-sbt-classifiers-cross-plugin/project/build.sbt
new file mode 100644
index 000000000..b090aa9d7
--- /dev/null
+++ b/sbt-app/src/sbt-test/dependency-management/i8026-update-sbt-classifiers-cross-plugin/project/build.sbt
@@ -0,0 +1 @@
+ThisBuild / pluginCrossBuild / sbtVersion := "2.0.0"
diff --git a/sbt-app/src/sbt-test/dependency-management/i8026-update-sbt-classifiers-cross-plugin/test b/sbt-app/src/sbt-test/dependency-management/i8026-update-sbt-classifiers-cross-plugin/test
new file mode 100644
index 000000000..00ad751bf
--- /dev/null
+++ b/sbt-app/src/sbt-test/dependency-management/i8026-update-sbt-classifiers-cross-plugin/test
@@ -0,0 +1 @@
+> updateSbtClassifiers