diff --git a/src/core/webview/webviewMessageHandler.ts b/src/core/webview/webviewMessageHandler.ts
index 63f4ce294e..7f3cd5a3de 100644
--- a/src/core/webview/webviewMessageHandler.ts
+++ b/src/core/webview/webviewMessageHandler.ts
@@ -979,11 +979,29 @@ export const webviewMessageHandler = async (
 		case "openMention":
 			openMention(getCurrentCwd(), message.text)
 			break
-		case "openExternal":
-			if (message.url) {
-				vscode.env.openExternal(vscode.Uri.parse(message.url))
+		case "openExternal": {
+			const url = message.url
+			if (typeof url === "string") {
+				try {
+					const uri = vscode.Uri.parse(url)
+					const isAllowedScheme = uri.scheme === "http" || uri.scheme === "https"
+					if (isAllowedScheme) {
+						await vscode.env.openExternal(uri)
+					} else {
+						console.warn(`Blocked external URL with disallowed scheme: ${url}`)
+						vscode.window.showErrorMessage(
+							t("common:errors.invalid_url_scheme") || "Invalid URL scheme. Only http/https are allowed.",
+						)
+					}
+				} catch (error) {
+					console.error("Failed to open external URL:", error)
+					vscode.window.showErrorMessage(
+						t("common:errors.open_external_failed") || "Failed to open external URL",
+					)
+				}
 			}
 			break
+		}
 		case "checkpointDiff":
 			const result = checkoutDiffPayloadSchema.safeParse(message.payload)
 
diff --git a/webview-ui/src/components/settings/ApiOptions.tsx b/webview-ui/src/components/settings/ApiOptions.tsx
index 4d4dae01bc..ed132421cb 100644
--- a/webview-ui/src/components/settings/ApiOptions.tsx
+++ b/webview-ui/src/components/settings/ApiOptions.tsx
@@ -442,7 +442,11 @@ const ApiOptions = ({
 					<label className="block font-medium mb-1">{t("settings:providers.apiProvider")}</label>
 					{docs && (
 						<div className="text-xs text-vscode-descriptionForeground">
-							<VSCodeLink href={docs.url} className="hover:text-vscode-foreground" target="_blank">
+							<VSCodeLink
+								href={docs.url}
+								className="hover:text-vscode-foreground"
+								target="_blank"
+								rel="noreferrer noopener">
 								{t("settings:providers.providerDocumentation", { provider: docs.name })}
 							</VSCodeLink>
 						</div>