diff --git a/multimodal/tarko/agent-server-next/src/services/ShareService.ts b/multimodal/tarko/agent-server-next/src/services/ShareService.ts
index ca585e3473..d60efa458a 100644
--- a/multimodal/tarko/agent-server-next/src/services/ShareService.ts
+++ b/multimodal/tarko/agent-server-next/src/services/ShareService.ts
@@ -31,6 +31,34 @@ export class ShareService {
     private server?: AgentServer,
   ) {}
 
+  private resolveWorkspaceImagePath(workspace: string, relativePath: string): string | null {
+    if (!relativePath || path.isAbsolute(relativePath)) {
+      return null;
+    }
+
+    const normalized = path.normalize(relativePath);
+    if (normalized.split(path.sep).includes('..')) {
+      return null;
+    }
+
+    const candidatePath = path.resolve(workspace, normalized);
+    if (!fs.existsSync(candidatePath)) {
+      return null;
+    }
+
+    try {
+      const realWorkspace = fs.realpathSync(workspace);
+      const realCandidate = fs.realpathSync(candidatePath);
+      const relative = path.relative(realWorkspace, realCandidate);
+      if (relative.startsWith('..') || path.isAbsolute(relative)) {
+        return null;
+      }
+      return realCandidate;
+    } catch (error) {
+      return null;
+    }
+  }
+
   /**
    * Share a session
    * @param sessionId Session ID to share
@@ -81,21 +109,21 @@ export class ShareService {
         processedEvents = await this.processWorkspaceImages(keyFrameEvents, metadata.workspace);
       }
 
-      if(!this.appConfig.webui) {
+      if (!this.appConfig.webui) {
         throw new Error('Cannot found webui config');
       }
 
-      if (this.appConfig.webui?.type === 'static' && !this.appConfig.webui?.staticPath ) {
+      if (this.appConfig.webui?.type === 'static' && !this.appConfig.webui?.staticPath) {
         throw new Error('Cannot found static path.');
       }
 
-      if(this.appConfig.webui?.type === 'remote' && !this.appConfig.webui?.remoteUrl) {
+      if (this.appConfig.webui?.type === 'remote' && !this.appConfig.webui?.remoteUrl) {
         throw new Error('Cannot found remote url.');
       }
 
       // Merge web UI config with agent constructor config
       const mergedWebUIConfig = mergeWebUIConfig(this.appConfig.webui, this.server);
-      
+
       const builder = new AgentUIBuilder({
         events: keyFrameEvents,
         sessionInfo: metadata,
@@ -243,8 +271,11 @@ export class ShareService {
       }
 
       try {
-        // Resolve absolute path
-        const absolutePath = path.resolve(workspace, relativePath);
+        // Resolve absolute path with workspace boundary checks
+        const absolutePath = this.resolveWorkspaceImagePath(workspace, relativePath);
+        if (!absolutePath) {
+          continue;
+        }
 
         // Check if file exists and is an image
         if (fs.existsSync(absolutePath) && this.isImageFile(absolutePath)) {
diff --git a/multimodal/tarko/agent-server-next/tests/share-path-traversal.test.ts b/multimodal/tarko/agent-server-next/tests/share-path-traversal.test.ts
new file mode 100644
index 0000000000..351327f092
--- /dev/null
+++ b/multimodal/tarko/agent-server-next/tests/share-path-traversal.test.ts
@@ -0,0 +1,85 @@
+/**
+ * Target path: multimodal/tarko/agent-server-next/tests/share-path-traversal.test.ts
+ */
+import { describe, expect, it } from 'vitest';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import { ShareService } from '../src/services/ShareService';
+
+const createWorkspace = () => {
+  const workspace = fs.mkdtempSync(path.join(os.tmpdir(), 'tars-workspace-'));
+  const imagesDir = path.join(workspace, 'images');
+  fs.mkdirSync(imagesDir, { recursive: true });
+  const insideImage = path.join(imagesDir, 'inside.png');
+  fs.writeFileSync(insideImage, 'inside');
+
+  const outsideDir = fs.mkdtempSync(path.join(os.tmpdir(), 'tars-outside-'));
+  const outsideImage = path.join(outsideDir, 'outside.png');
+  fs.writeFileSync(outsideImage, 'outside');
+
+  const cleanup = () => {
+    fs.rmSync(workspace, { recursive: true, force: true });
+    fs.rmSync(outsideDir, { recursive: true, force: true });
+  };
+
+  return { workspace, insideImage, outsideImage, cleanup };
+};
+
+const buildService = () => new ShareService({} as any, null as any, undefined);
+
+describe('ShareService.resolveWorkspaceImagePath', () => {
+  it('allows workspace relative paths', () => {
+    const { workspace, insideImage, cleanup } = createWorkspace();
+    try {
+      const service = buildService();
+      const resolvePath = (service as any).resolveWorkspaceImagePath.bind(service);
+      const resolved = resolvePath(workspace, 'images/inside.png');
+      expect(resolved).toBe(insideImage);
+    } finally {
+      cleanup();
+    }
+  });
+
+  it('rejects traversal paths', () => {
+    const { workspace, cleanup } = createWorkspace();
+    try {
+      const service = buildService();
+      const resolvePath = (service as any).resolveWorkspaceImagePath.bind(service);
+      const resolved = resolvePath(workspace, '../outside.png');
+      expect(resolved).toBeNull();
+    } finally {
+      cleanup();
+    }
+  });
+
+  it('rejects absolute paths', () => {
+    const { workspace, insideImage, cleanup } = createWorkspace();
+    try {
+      const service = buildService();
+      const resolvePath = (service as any).resolveWorkspaceImagePath.bind(service);
+      const resolved = resolvePath(workspace, insideImage);
+      expect(resolved).toBeNull();
+    } finally {
+      cleanup();
+    }
+  });
+
+  it('rejects symlink escape when supported', () => {
+    const { workspace, outsideImage, cleanup } = createWorkspace();
+    const linkPath = path.join(workspace, 'images', 'link.png');
+    try {
+      try {
+        fs.symlinkSync(outsideImage, linkPath);
+      } catch {
+        return;
+      }
+      const service = buildService();
+      const resolvePath = (service as any).resolveWorkspaceImagePath.bind(service);
+      const resolved = resolvePath(workspace, 'images/link.png');
+      expect(resolved).toBeNull();
+    } finally {
+      cleanup();
+    }
+  });
+});
diff --git a/multimodal/tarko/agent-server/src/services/ShareService.ts b/multimodal/tarko/agent-server/src/services/ShareService.ts
index 11bb86fec6..154fe81d58 100644
--- a/multimodal/tarko/agent-server/src/services/ShareService.ts
+++ b/multimodal/tarko/agent-server/src/services/ShareService.ts
@@ -31,6 +31,34 @@ export class ShareService {
     private server?: AgentServer,
   ) {}
 
+  private resolveWorkspaceImagePath(workspace: string, relativePath: string): string | null {
+    if (!relativePath || path.isAbsolute(relativePath)) {
+      return null;
+    }
+
+    const normalized = path.normalize(relativePath);
+    if (normalized.split(path.sep).includes('..')) {
+      return null;
+    }
+
+    const candidatePath = path.resolve(workspace, normalized);
+    if (!fs.existsSync(candidatePath)) {
+      return null;
+    }
+
+    try {
+      const realWorkspace = fs.realpathSync(workspace);
+      const realCandidate = fs.realpathSync(candidatePath);
+      const relative = path.relative(realWorkspace, realCandidate);
+      if (relative.startsWith('..') || path.isAbsolute(relative)) {
+        return null;
+      }
+      return realCandidate;
+    } catch (error) {
+      return null;
+    }
+  }
+
   /**
    * Share a session
    * @param sessionId Session ID to share
@@ -239,8 +267,11 @@ export class ShareService {
       }
 
       try {
-        // Resolve absolute path
-        const absolutePath = path.resolve(workspace, relativePath);
+        // Resolve absolute path with workspace boundary checks
+        const absolutePath = this.resolveWorkspaceImagePath(workspace, relativePath);
+        if (!absolutePath) {
+          continue;
+        }
 
         // Check if file exists and is an image
         if (fs.existsSync(absolutePath) && this.isImageFile(absolutePath)) {
diff --git a/multimodal/tarko/agent-server/tests/share-path-traversal.test.ts b/multimodal/tarko/agent-server/tests/share-path-traversal.test.ts
new file mode 100644
index 0000000000..8cbab79ca7
--- /dev/null
+++ b/multimodal/tarko/agent-server/tests/share-path-traversal.test.ts
@@ -0,0 +1,85 @@
+/**
+ * Target path: multimodal/tarko/agent-server/tests/share-path-traversal.test.ts
+ */
+import { describe, expect, it } from 'vitest';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import { ShareService } from '../src/services/ShareService';
+
+const createWorkspace = () => {
+  const workspace = fs.mkdtempSync(path.join(os.tmpdir(), 'tars-workspace-'));
+  const imagesDir = path.join(workspace, 'images');
+  fs.mkdirSync(imagesDir, { recursive: true });
+  const insideImage = path.join(imagesDir, 'inside.png');
+  fs.writeFileSync(insideImage, 'inside');
+
+  const outsideDir = fs.mkdtempSync(path.join(os.tmpdir(), 'tars-outside-'));
+  const outsideImage = path.join(outsideDir, 'outside.png');
+  fs.writeFileSync(outsideImage, 'outside');
+
+  const cleanup = () => {
+    fs.rmSync(workspace, { recursive: true, force: true });
+    fs.rmSync(outsideDir, { recursive: true, force: true });
+  };
+
+  return { workspace, insideImage, outsideImage, cleanup };
+};
+
+const buildService = () => new ShareService({} as any, null as any, undefined);
+
+describe('ShareService.resolveWorkspaceImagePath', () => {
+  it('allows workspace relative paths', () => {
+    const { workspace, insideImage, cleanup } = createWorkspace();
+    try {
+      const service = buildService();
+      const resolvePath = (service as any).resolveWorkspaceImagePath.bind(service);
+      const resolved = resolvePath(workspace, 'images/inside.png');
+      expect(resolved).toBe(insideImage);
+    } finally {
+      cleanup();
+    }
+  });
+
+  it('rejects traversal paths', () => {
+    const { workspace, cleanup } = createWorkspace();
+    try {
+      const service = buildService();
+      const resolvePath = (service as any).resolveWorkspaceImagePath.bind(service);
+      const resolved = resolvePath(workspace, '../outside.png');
+      expect(resolved).toBeNull();
+    } finally {
+      cleanup();
+    }
+  });
+
+  it('rejects absolute paths', () => {
+    const { workspace, insideImage, cleanup } = createWorkspace();
+    try {
+      const service = buildService();
+      const resolvePath = (service as any).resolveWorkspaceImagePath.bind(service);
+      const resolved = resolvePath(workspace, insideImage);
+      expect(resolved).toBeNull();
+    } finally {
+      cleanup();
+    }
+  });
+
+  it('rejects symlink escape when supported', () => {
+    const { workspace, outsideImage, cleanup } = createWorkspace();
+    const linkPath = path.join(workspace, 'images', 'link.png');
+    try {
+      try {
+        fs.symlinkSync(outsideImage, linkPath);
+      } catch {
+        return;
+      }
+      const service = buildService();
+      const resolvePath = (service as any).resolveWorkspaceImagePath.bind(service);
+      const resolved = resolvePath(workspace, 'images/link.png');
+      expect(resolved).toBeNull();
+    } finally {
+      cleanup();
+    }
+  });
+});