diff --git a/hudi-spark-datasource/hudi-spark-common/src/main/scala/org/apache/hudi/HoodieSparkSqlWriter.scala b/hudi-spark-datasource/hudi-spark-common/src/main/scala/org/apache/hudi/HoodieSparkSqlWriter.scala
index aaa79929256f6..973ef8884f2a0 100644
--- a/hudi-spark-datasource/hudi-spark-common/src/main/scala/org/apache/hudi/HoodieSparkSqlWriter.scala
+++ b/hudi-spark-datasource/hudi-spark-common/src/main/scala/org/apache/hudi/HoodieSparkSqlWriter.scala
@@ -24,7 +24,7 @@ import org.apache.hudi.DataSourceWriteOptions._
 import org.apache.hudi.HoodieConversionUtils.{toProperties, toScalaOption}
 import org.apache.hudi.HoodieSchemaConversionUtils.{convertStructTypeToHoodieSchema, getRecordNameAndNamespace}
 import org.apache.hudi.HoodieSparkSqlWriter.StreamingWriteParams
-import org.apache.hudi.HoodieSparkSqlWriterInternal.{handleInsertDuplicates, shouldDropDuplicatesForInserts, shouldFailWhenDuplicatesFound}
+import org.apache.hudi.HoodieSparkSqlWriterInternal.{handleInsertDuplicates, refreshSparkCatalogTableCache, shouldDropDuplicatesForInserts, shouldFailWhenDuplicatesFound}
 import org.apache.hudi.HoodieWriterUtils._
 import org.apache.hudi.client.{HoodieWriteResult, SparkRDDWriteClient}
 import org.apache.hudi.client.common.HoodieSparkEngineContext
@@ -81,6 +81,7 @@ import java.util.function.BiConsumer
 import scala.collection.JavaConverters._
 import scala.collection.mutable
 import scala.util.{Failure, Success, Try}
+import scala.util.control.NonFatal
 
 object HoodieSparkSqlWriter {
 
@@ -947,13 +948,7 @@ class HoodieSparkSqlWriterInternal {
     // Since Hive tables are now synced as Spark data source tables which are cached after Spark SQL queries
     // we must invalidate this table in the cache so writes are reflected in later queries
     if (metaSyncEnabled) {
-      getHiveTableNames(hoodieConfig).foreach(name => {
-        val syncDb = hoodieConfig.getStringOrDefault(HIVE_DATABASE)
-        val qualifiedTableName = String.join(".", syncDb, name)
-        if (spark.catalog.databaseExists(syncDb) && spark.catalog.tableExists(qualifiedTableName)) {
-          spark.catalog.refreshTable(qualifiedTableName)
-        }
-      })
+      refreshSparkCatalogTableCache(spark, hoodieConfig.getStringOrDefault(HIVE_DATABASE), getHiveTableNames(hoodieConfig))
     }
     true
   }
@@ -1181,6 +1176,45 @@ class HoodieSparkSqlWriterInternal {
 }
 
 object HoodieSparkSqlWriterInternal {
+  private val log = LoggerFactory.getLogger(classOf[HoodieSparkSqlWriterInternal])
+
+  /**
+   * Best-effort invalidation of the Spark catalog relation cache for the just-synced table(s), so
+   * subsequent reads in the same Spark session reflect the new write.
+   *
+   * The table name is always qualified with the sync database ([[HIVE_DATABASE]] /
+   * `hoodie.datasource.hive_sync.database`) so a same-named table in another database - in
+   * particular the session's current/`default` database - is never resolved and refreshed by
+   * mistake (HUDI-18139).
+   *
+   * Any failure is logged and swallowed: by this point the data has already been committed and
+   * meta-synced successfully, so a cache-invalidation problem (a transient catalog error, or a
+   * same-named table backed by storage the writer cannot access) must never fail the write.
+   */
+  def refreshSparkCatalogTableCache(spark: SparkSession, syncDb: String, tableNames: Seq[String]): Unit = {
+    try {
+      if (spark.catalog.databaseExists(syncDb)) {
+        tableNames.foreach { name =>
+          val qualifiedTableName = String.join(".", syncDb, name)
+          try {
+            if (spark.catalog.tableExists(qualifiedTableName)) {
+              spark.catalog.refreshTable(qualifiedTableName)
+            }
+          } catch {
+            case NonFatal(e) =>
+              log.warn(s"Failed to refresh Spark catalog cache for table '$qualifiedTableName' after a " +
+                s"successful write and meta-sync; the write is already committed. Skipping cache " +
+                s"invalidation for this table.", e)
+          }
+        }
+      }
+    } catch {
+      case NonFatal(e) =>
+        log.warn(s"Failed to refresh Spark catalog cache for database '$syncDb' after a successful write " +
+          s"and meta-sync; the write is already committed. Skipping cache invalidation.", e)
+    }
+  }
+
   // Check if duplicates should be dropped.
   def shouldDropDuplicatesForInserts(hoodieConfig: HoodieConfig): Boolean = {
     hoodieConfig.contains(INSERT_DUP_POLICY) &&
diff --git a/hudi-spark-datasource/hudi-spark/src/test/scala/org/apache/hudi/functional/TestSparkCatalogCacheRefresh.scala b/hudi-spark-datasource/hudi-spark/src/test/scala/org/apache/hudi/functional/TestSparkCatalogCacheRefresh.scala
new file mode 100644
index 0000000000000..0e4a60ff83854
--- /dev/null
+++ b/hudi-spark-datasource/hudi-spark/src/test/scala/org/apache/hudi/functional/TestSparkCatalogCacheRefresh.scala
@@ -0,0 +1,127 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hudi.functional
+
+import org.apache.hudi.HoodieSparkSqlWriterInternal
+
+import org.apache.commons.io.FileUtils
+import org.apache.spark.sql.SaveMode
+import org.apache.spark.sql.hudi.common.HoodieSparkSqlTestBase
+
+import java.io.File
+
+/**
+ * Regression test for HUDI-18139.
+ *
+ * After a successful write + meta-sync, Hudi invalidates the Spark catalog relation cache for the
+ * synced table so later reads in the same session see the new data. Two failure modes are covered:
+ *
+ *  1. The refresh must target the table in the SYNC database, never a same-named table in the
+ *     session's current/`default` database (which, in the reported issue, pointed at a bucket the
+ *     writer could not access and produced an AccessDenied).
+ *  2. The refresh is best-effort: even if it fails (e.g. the table's storage is momentarily
+ *     inaccessible), it must NOT fail the write, which has already been committed and synced.
+ */
+class TestSparkCatalogCacheRefresh extends HoodieSparkSqlTestBase {
+
+  test("HUDI-18139: post-sync catalog refresh targets the sync db and never fails a committed write") {
+    withTempDir { tmp =>
+      val syncDb = "hudi_18139_sync_db"
+      val tableName = "refresh_t"
+      val pathDefault = new File(tmp, "default_refresh_t").getCanonicalPath
+      val pathSyncDb = new File(tmp, "syncdb_refresh_t").getCanonicalPath
+      try {
+        spark.sql(s"create database if not exists $syncDb")
+        // Same table name `refresh_t` in two databases, backed by different locations.
+        spark.sql(
+          s"""create table default.$tableName (id int, name string, ts long) using hudi
+             | location '$pathDefault'
+             | tblproperties (primaryKey = 'id', preCombineField = 'ts')""".stripMargin)
+        spark.sql(s"insert into default.$tableName values (1, 'a', 1)")
+        spark.sql(
+          s"""create table $syncDb.$tableName (id int, name string, ts long) using hudi
+             | location '$pathSyncDb'
+             | tblproperties (primaryKey = 'id', preCombineField = 'ts')""".stripMargin)
+        spark.sql(s"insert into $syncDb.$tableName values (1, 'a', 1)")
+
+        // Current database is `default`; break the unrelated default.refresh_t so that ANY resolution
+        // of it fails (mimics the inaccessible wrong-bucket table from the issue).
+        spark.sql("use default")
+        FileUtils.deleteDirectory(new File(pathDefault))
+
+        // (1) Refreshing for the sync db must target `$syncDb.refresh_t` (intact), never the broken
+        //     `default.refresh_t`. A buggy (unqualified) refresh would resolve `default.refresh_t`
+        //     and throw here.
+        HoodieSparkSqlWriterInternal.refreshSparkCatalogTableCache(spark, syncDb, Seq(tableName))
+
+        // (2) Best-effort: even when the intended table's storage is also inaccessible, the refresh
+        //     must swallow the error and not fail the (already committed + synced) write.
+        FileUtils.deleteDirectory(new File(pathSyncDb))
+        HoodieSparkSqlWriterInternal.refreshSparkCatalogTableCache(spark, syncDb, Seq(tableName))
+      } finally {
+        spark.sql("use default")
+        spark.sql(s"drop table if exists default.$tableName")
+        spark.sql(s"drop table if exists $syncDb.$tableName")
+        spark.sql(s"drop database if exists $syncDb cascade")
+      }
+    }
+  }
+
+  test("HUDI-18139: refresh invalidates the cached relation so newly committed data becomes visible") {
+    withTempDir { tmp =>
+      val syncDb = "hudi_18139_fresh_db"
+      val tableName = "fresh_t"
+      val path = new File(tmp, "fresh_t").getCanonicalPath
+      try {
+        spark.sql(s"create database if not exists $syncDb")
+        spark.sql(
+          s"""create table $syncDb.$tableName (id int, name string, ts long) using hudi
+             | location '$path'
+             | tblproperties (primaryKey = 'id', preCombineField = 'ts')""".stripMargin)
+        spark.sql(s"insert into $syncDb.$tableName values (1, 'a', 1)")
+
+        // Read once to cache the catalog relation (file listing).
+        assertResult(1)(spark.table(s"$syncDb.$tableName").count())
+
+        // Append a row directly to the table's storage, bypassing the catalog so the cached relation
+        // is now stale - this mimics the just-completed write whose data Hudi must make visible.
+        spark.sql("select 2 as id, 'b' as name, cast(2 as bigint) as ts")
+          .write.format("hudi")
+          .option("hoodie.datasource.write.recordkey.field", "id")
+          .option("hoodie.datasource.write.precombine.field", "ts")
+          .option("hoodie.datasource.write.partitionpath.field", "")
+          .option("hoodie.table.name", tableName)
+          .mode(SaveMode.Append)
+          .save(path)
+
+        // Without refresh the cached relation still reports the stale row count, proving the refresh
+        // below is doing real work (not a no-op).
+        assertResult(1)(spark.table(s"$syncDb.$tableName").count())
+
+        HoodieSparkSqlWriterInternal.refreshSparkCatalogTableCache(spark, syncDb, Seq(tableName))
+
+        assertResult(2)(spark.table(s"$syncDb.$tableName").count())
+      } finally {
+        spark.sql("use default")
+        spark.sql(s"drop table if exists $syncDb.$tableName")
+        spark.sql(s"drop database if exists $syncDb cascade")
+      }
+    }
+  }
+}