diff --git a/src/__tests__/deploy-integration.test.ts b/src/__tests__/deploy-integration.test.ts
index e825dfb..ab13209 100644
--- a/src/__tests__/deploy-integration.test.ts
+++ b/src/__tests__/deploy-integration.test.ts
@@ -547,4 +547,76 @@ describe("deploy command (mocked shell)", () => {
       }
     }
   })
+
+  function setupUnlinkedTestDir(name: string, packageName: string) {
+    const testDir = join(fixturesDir, name)
+    mkdirSync(testDir, { recursive: true })
+    writeFileSync(
+      join(testDir, "package.json"),
+      JSON.stringify({ name: packageName }),
+    )
+    return testDir
+  }
+
+  it("should not pass a package.json name with shell metacharacters into the link command (CWE-78)", async () => {
+    vi.spyOn(process, "exit").mockImplementation(code => {
+      throw new ExitError(code as number)
+    })
+    const logSpy = vi.spyOn(console, "log").mockImplementation(() => {})
+    vi.spyOn(console, "error").mockImplementation(() => {})
+
+    const maliciousName = '"; touch /tmp/pwned; echo "'
+    const testDir = setupUnlinkedTestDir("malicious-name", maliciousName)
+
+    setupExecMock({
+      "vercel --version": "Vercel CLI 33.0.0",
+      "vercel whoami": "test-user",
+      "vercel deploy --prod": new Error("stop after link"),
+    })
+
+    process.chdir(testDir)
+
+    const { deployCommand } = await import("../cli/commands/deploy.js")
+    await expect(
+      deployCommand.parseAsync(["--host", "vercel"], { from: "user" }),
+    ).rejects.toThrow(ExitError)
+
+    for (const call of execSyncMock.mock.calls) {
+      expect(String(call[0])).not.toContain(maliciousName)
+      expect(String(call[0])).not.toContain("touch /tmp/pwned")
+    }
+
+    expect(logSpy).toHaveBeenCalledWith(
+      expect.stringContaining("not a valid Vercel project name"),
+    )
+  })
+
+  it("should pass a valid package.json name through to the link command", async () => {
+    vi.spyOn(process, "exit").mockImplementation(code => {
+      throw new ExitError(code as number)
+    })
+    vi.spyOn(console, "log").mockImplementation(() => {})
+    vi.spyOn(console, "error").mockImplementation(() => {})
+
+    const testDir = setupUnlinkedTestDir("valid-name", "@scope/my-tool")
+
+    setupExecMock({
+      "vercel --version": "Vercel CLI 33.0.0",
+      "vercel whoami": "test-user",
+      "vercel link": "",
+      "vercel deploy --prod": new Error("stop after link"),
+    })
+
+    process.chdir(testDir)
+
+    const { deployCommand } = await import("../cli/commands/deploy.js")
+    await expect(
+      deployCommand.parseAsync(["--host", "vercel"], { from: "user" }),
+    ).rejects.toThrow(ExitError)
+
+    expect(execSyncMock).toHaveBeenCalledWith(
+      expect.stringContaining("--project=my-tool"),
+      expect.anything(),
+    )
+  })
 })
diff --git a/src/cli/commands/deploy.ts b/src/cli/commands/deploy.ts
index fa3dd95..c3ef982 100644
--- a/src/cli/commands/deploy.ts
+++ b/src/cli/commands/deploy.ts
@@ -78,6 +78,15 @@ export function isSensitiveEnvVar(name: string): boolean {
   return SENSITIVE_PATTERN.test(name)
 }
 
+// Vercel project names may only contain lowercase letters, numbers, ".", "_"
+// and "-" (max 100 chars). Anything outside this set must never reach a
+// shell-interpolated command string (execCmd runs via execSync/"sh -c").
+const VERCEL_PROJECT_NAME_PATTERN = /^[a-z0-9][a-z0-9._-]{0,99}$/
+
+export function isValidVercelProjectName(name: string): boolean {
+  return VERCEL_PROJECT_NAME_PATTERN.test(name)
+}
+
 export function extractDeploymentUrl(output: string): string | undefined {
   for (const line of output.split("\n")) {
     const match = line.match(/https:\/\/[\w-]+\.vercel\.app/)
@@ -219,7 +228,16 @@ async function deployToVercel(options: DeployOptions): Promise<void> {
           name?: string
         }
         if (pkg.name) {
-          projectName = pkg.name.replace(/^@[^/]+\//, "")
+          const candidate = pkg.name.replace(/^@[^/]+\//, "")
+          if (isValidVercelProjectName(candidate)) {
+            projectName = candidate
+          } else {
+            console.log(
+              pc.yellow(
+                `  Warning: package.json name "${pkg.name}" is not a valid Vercel project name — omitting --project flag`,
+              ),
+            )
+          }
         }
       }
     } catch {