diff --git a/resources/js/components/fieldtypes/assets/AssetsFieldtype.vue b/resources/js/components/fieldtypes/assets/AssetsFieldtype.vue
index d1c52c6dc5a..ea6cc68c59e 100644
--- a/resources/js/components/fieldtypes/assets/AssetsFieldtype.vue
+++ b/resources/js/components/fieldtypes/assets/AssetsFieldtype.vue
@@ -201,6 +201,7 @@ import { isEqual } from 'lodash-es';
 import { Button, Dropdown, DropdownMenu, DropdownItem, Stack } from '@/components/ui';
 import ItemActions from '@/components/actions/ItemActions.vue';
 import useCheckerboard from '@/composables/checkerboard.js';
+import { dedupeInFlight } from '@/util/dedupeInFlight.js';
 
 export default {
     components: {
@@ -496,14 +497,16 @@ export default {
 
             this.loading = true;
 
-            this.$axios
-                .post(cp_url('assets-fieldtype'), {
-                    assets,
-                })
-                .then((response) => {
-                    this.assets = response.data;
-                    this.loading = false;
-                });
+            const cacheKey = JSON.stringify([...assets].slice().sort());
+
+            dedupeInFlight('assets-fieldtype', cacheKey, () =>
+                this.$axios.post(cp_url('assets-fieldtype'), { assets }),
+            ).then((response) => {
+                // Clone so mutations on one field's asset rows don't bleed into others
+                // sharing the same in-flight response.
+                this.assets = clone(response.data);
+                this.loading = false;
+            });
         },
 
         /**
diff --git a/resources/js/components/fieldtypes/bard/Image.vue b/resources/js/components/fieldtypes/bard/Image.vue
index 0dead0b49ed..5f6fc51cab7 100644
--- a/resources/js/components/fieldtypes/bard/Image.vue
+++ b/resources/js/components/fieldtypes/bard/Image.vue
@@ -71,6 +71,7 @@ import { NodeViewWrapper } from '@tiptap/vue-3';
 import Selector from '../../assets/Selector.vue';
 import { Input, Button, Stack } from '@ui';
 import { containerContextKey } from '@/components/ui/Publish/Container.vue';
+import { dedupeInFlight } from '@/util/dedupeInFlight.js';
 
 export default {
     mixins: [Asset],
@@ -184,13 +185,13 @@ export default {
                 return;
             }
 
-            this.$axios
-                .post(cp_url('assets-fieldtype'), {
-                    assets: [id],
-                })
-                .then((response) => {
-                    this.setAsset(response.data[0]);
-                });
+            const cacheKey = JSON.stringify([id]);
+
+            dedupeInFlight('assets-fieldtype', cacheKey, () =>
+                this.$axios.post(cp_url('assets-fieldtype'), { assets: [id] }),
+            ).then((response) => {
+                this.setAsset(response.data[0]);
+            });
         },
 
         setAsset(asset) {
diff --git a/resources/js/components/fieldtypes/markdown/MarkdownFieldtype.vue b/resources/js/components/fieldtypes/markdown/MarkdownFieldtype.vue
index e2b6adb043c..c140ecfd078 100644
--- a/resources/js/components/fieldtypes/markdown/MarkdownFieldtype.vue
+++ b/resources/js/components/fieldtypes/markdown/MarkdownFieldtype.vue
@@ -186,6 +186,7 @@ import Uploader from '../../assets/Uploader.vue';
 import Uploads from '../../assets/Uploads.vue';
 import MarkdownToolbar from './MarkdownToolbar.vue';
 import { useContentDirection } from '@/composables/content-direction';
+import { dedupeInFlight } from '@/util/dedupeInFlight.js';
 // Keymaps
 import 'codemirror/keymap/sublime';
 
@@ -587,8 +588,12 @@ export default {
             this.closeAssetSelector();
             this.selectedAssets = [];
 
-            this.$axios.post(cp_url('assets-fieldtype'), { assets }).then(({ data }) => {
-                data.forEach(asset => {
+            const cacheKey = JSON.stringify([...assets].slice().sort());
+
+            dedupeInFlight('assets-fieldtype', cacheKey, () =>
+                this.$axios.post(cp_url('assets-fieldtype'), { assets }),
+            ).then(({ data }) => {
+                data.forEach((asset) => {
                     const alt = asset.values.alt || '';
                     const url = encodeURI(`statamic://${asset.reference}`);
                     const method = assets.length === 1 ? 'insert' : 'append';
diff --git a/resources/js/tests/dedupeInFlight.test.js b/resources/js/tests/dedupeInFlight.test.js
new file mode 100644
index 00000000000..02a3ddbb189
--- /dev/null
+++ b/resources/js/tests/dedupeInFlight.test.js
@@ -0,0 +1,71 @@
+import { describe, test, expect, vi } from 'vitest';
+import { dedupeInFlight } from '../util/dedupeInFlight';
+
+function deferred() {
+    let resolve, reject;
+    const promise = new Promise((res, rej) => {
+        resolve = res;
+        reject = rej;
+    });
+    return { promise, resolve, reject };
+}
+
+describe('dedupeInFlight', () => {
+    test('calls the factory once for concurrent callers sharing a key', async () => {
+        const d = deferred();
+        const factory = vi.fn(() => d.promise);
+
+        const a = dedupeInFlight('ns', 'key', factory);
+        const b = dedupeInFlight('ns', 'key', factory);
+
+        expect(factory).toHaveBeenCalledTimes(1);
+
+        d.resolve('value');
+
+        expect(await a).toBe('value');
+        expect(await b).toBe('value');
+    });
+
+    test('calls the factory immediately rather than deferring it', () => {
+        const factory = vi.fn(() => Promise.resolve());
+
+        dedupeInFlight('ns', 'sync', factory);
+
+        expect(factory).toHaveBeenCalledTimes(1);
+    });
+
+    test('does not share between different keys or namespaces', async () => {
+        const factory = vi.fn(() => Promise.resolve());
+
+        dedupeInFlight('ns', 'one', factory);
+        dedupeInFlight('ns', 'two', factory);
+        dedupeInFlight('other', 'one', factory);
+
+        expect(factory).toHaveBeenCalledTimes(3);
+    });
+
+    test('releases the entry once settled so a later call fetches fresh', async () => {
+        const factory = vi.fn(() => Promise.resolve('value'));
+
+        await dedupeInFlight('ns', 'settled', factory);
+        await dedupeInFlight('ns', 'settled', factory);
+
+        expect(factory).toHaveBeenCalledTimes(2);
+    });
+
+    test('rejects every caller when the shared work fails, and releases the entry', async () => {
+        const d = deferred();
+        const failing = vi.fn(() => d.promise);
+
+        const a = dedupeInFlight('ns', 'failure', failing);
+        const b = dedupeInFlight('ns', 'failure', failing);
+
+        d.reject(new Error('nope'));
+
+        await expect(a).rejects.toThrow('nope');
+        await expect(b).rejects.toThrow('nope');
+
+        await dedupeInFlight('ns', 'failure', () => Promise.resolve('ok'));
+        expect(failing).toHaveBeenCalledTimes(1);
+    });
+});
diff --git a/resources/js/util/dedupeInFlight.js b/resources/js/util/dedupeInFlight.js
new file mode 100644
index 00000000000..160ed23161a
--- /dev/null
+++ b/resources/js/util/dedupeInFlight.js
@@ -0,0 +1,36 @@
+const namespaces = new Map();
+
+/**
+ * Share identical in-flight async work across callers within a namespace.
+ * Once the promise settles the entry is removed — this is not a settled-result cache.
+ *
+ * The factory is invoked synchronously so callers that assert immediately after
+ * kicking off the request still see the underlying work start.
+ *
+ * @param {string} namespace
+ * @param {string} key
+ * @param {() => Promise<any>} factory
+ * @returns {Promise<any>}
+ */
+export function dedupeInFlight(namespace, key, factory) {
+    let map = namespaces.get(namespace);
+
+    if (!map) {
+        map = new Map();
+        namespaces.set(namespace, map);
+    }
+
+    let entry = map.get(key);
+
+    if (entry) return entry;
+
+    entry = Promise.resolve(factory()).finally(() => {
+        if (map.get(key) === entry) {
+            map.delete(key);
+        }
+    });
+
+    map.set(key, entry);
+
+    return entry;
+}