diff --git a/src/cli/cron-cli/register.cron-edit.ts b/src/cli/cron-cli/register.cron-edit.ts
index 0afda904570..b7afc0d9bc9 100644
--- a/src/cli/cron-cli/register.cron-edit.ts
+++ b/src/cli/cron-cli/register.cron-edit.ts
@@ -186,7 +186,11 @@ export function registerCronEditCommand(cron: Command) {
             patch.sessionTarget = sessionTarget;
           }
           if (typeof opts.wake === "string") {
-            patch.wakeMode = opts.wake;
+            const wakeMode = opts.wake.trim();
+            if (wakeMode !== "now" && wakeMode !== "next-heartbeat") {
+              throw new Error("--wake must be now or next-heartbeat");
+            }
+            patch.wakeMode = wakeMode;
           }
           if (opts.agent && opts.clearAgent) {
             throw new Error("Use --agent or --clear-agent, not both");
@@ -229,10 +233,20 @@ export function registerCronEditCommand(cron: Command) {
           const model = normalizeOptionalString(opts.model);
           const thinking = normalizeOptionalString(opts.thinking);
           const toolsAllow = parseCronToolsAllow(opts.tools);
-          const timeoutSeconds = opts.timeoutSeconds
-            ? Number.parseInt(String(opts.timeoutSeconds), 10)
-            : undefined;
-          const hasTimeoutSeconds = Boolean(timeoutSeconds && Number.isFinite(timeoutSeconds));
+          const rawTimeoutSeconds =
+            opts.timeoutSeconds === undefined ? undefined : String(opts.timeoutSeconds).trim();
+          if (rawTimeoutSeconds !== undefined && !/^\d+$/u.test(rawTimeoutSeconds)) {
+            throw new Error("Invalid --timeout-seconds (must be a positive integer).");
+          }
+          const timeoutSeconds =
+            rawTimeoutSeconds === undefined ? undefined : Number(rawTimeoutSeconds);
+          const hasTimeoutSeconds =
+            typeof timeoutSeconds === "number" &&
+            Number.isSafeInteger(timeoutSeconds) &&
+            timeoutSeconds > 0;
+          if (rawTimeoutSeconds !== undefined && !hasTimeoutSeconds) {
+            throw new Error("Invalid --timeout-seconds (must be a positive integer).");
+          }
           const hasDeliveryModeFlag = opts.announce || typeof opts.deliver === "boolean";
           const threadId = parseCronThreadIdOption(opts.threadId);
           const hasDeliveryThreadId = typeof threadId === "number";
diff --git a/src/cli/parse-timeout.test.ts b/src/cli/parse-timeout.test.ts
index d478827de15..f29d51e2a84 100644
--- a/src/cli/parse-timeout.test.ts
+++ b/src/cli/parse-timeout.test.ts
@@ -10,6 +10,9 @@ describe("parseTimeoutMs", () => {
     expect(parseTimeoutMs(undefined)).toBeUndefined();
     expect(parseTimeoutMs("")).toBeUndefined();
     expect(parseTimeoutMs("nope")).toBeUndefined();
+    expect(parseTimeoutMs("10abc")).toBeUndefined();
+    expect(parseTimeoutMs("1.5")).toBeUndefined();
+    expect(parseTimeoutMs("0")).toBeUndefined();
   });
 });
 
@@ -40,4 +43,12 @@ describe("parseTimeoutMsWithFallback", () => {
     expect(() => parseTimeoutMsWithFallback("0", 3000)).toThrow('Received: "0"');
     expect(() => parseTimeoutMsWithFallback("-1", 3000)).toThrow('Received: "-1"');
   });
+
+  it("throws on malformed or unsafe parsed values", () => {
+    expect(() => parseTimeoutMsWithFallback("10abc", 3000)).toThrow('Received: "10abc"');
+    expect(() => parseTimeoutMsWithFallback("1.5", 3000)).toThrow('Received: "1.5"');
+    expect(() => parseTimeoutMsWithFallback(String(Number.MAX_SAFE_INTEGER + 1), 3000)).toThrow(
+      "Received",
+    );
+  });
 });
diff --git a/src/cli/parse-timeout.ts b/src/cli/parse-timeout.ts
index 712dc8c757a..d53a4d43ec6 100644
--- a/src/cli/parse-timeout.ts
+++ b/src/cli/parse-timeout.ts
@@ -12,9 +12,12 @@ export function parseTimeoutMs(raw: unknown): number | undefined {
     if (!trimmed) {
       return undefined;
     }
-    value = Number.parseInt(trimmed, 10);
+    if (!/^\d+$/u.test(trimmed)) {
+      return undefined;
+    }
+    value = Number(trimmed);
   }
-  return Number.isFinite(value) ? value : undefined;
+  return Number.isSafeInteger(value) && value > 0 ? value : undefined;
 }
 
 function invalidTimeout(value?: string): Error {
@@ -53,8 +56,11 @@ export function parseTimeoutMsWithFallback(
     return fallbackMs;
   }
 
-  const parsed = Number.parseInt(value, 10);
-  if (!Number.isFinite(parsed) || parsed <= 0) {
+  if (!/^\d+$/u.test(value)) {
+    throw invalidTimeout(value);
+  }
+  const parsed = Number(value);
+  if (!Number.isSafeInteger(parsed) || parsed <= 0) {
     throw invalidTimeout(value);
   }
   return parsed;
diff --git a/src/cli/update-cli/shared.command-runner.test.ts b/src/cli/update-cli/shared.command-runner.test.ts
index 7e1f3ab7f37..2d097c3e010 100644
--- a/src/cli/update-cli/shared.command-runner.test.ts
+++ b/src/cli/update-cli/shared.command-runner.test.ts
@@ -60,10 +60,11 @@ describe("createGlobalCommandRunner", () => {
       expect(parseTimeoutMsOrExit("0")).toBeNull();
       expect(parseTimeoutMsOrExit("-1")).toBeNull();
       expect(parseTimeoutMsOrExit("   ")).toBeNull();
+      expect(parseTimeoutMsOrExit(String(Number.MAX_SAFE_INTEGER))).toBeNull();
 
-      expect(error).toHaveBeenCalledTimes(5);
+      expect(error).toHaveBeenCalledTimes(6);
       expect(error).toHaveBeenCalledWith("--timeout must be a positive integer (seconds)");
-      expect(exit).toHaveBeenCalledTimes(5);
+      expect(exit).toHaveBeenCalledTimes(6);
       expect(exit).toHaveBeenCalledWith(1);
     } finally {
       error.mockRestore();
diff --git a/src/cli/update-cli/shared.ts b/src/cli/update-cli/shared.ts
index 0b1d153da1f..2ac30f6b7c9 100644
--- a/src/cli/update-cli/shared.ts
+++ b/src/cli/update-cli/shared.ts
@@ -52,6 +52,7 @@ export type UpdateWizardOptions = {
 };
 
 const INVALID_TIMEOUT_ERROR = "--timeout must be a positive integer (seconds)";
+const MAX_SAFE_TIMEOUT_SECONDS = Math.floor(Number.MAX_SAFE_INTEGER / 1000);
 
 export function parseTimeoutMsOrExit(timeout?: string): number | undefined | null {
   if (timeout === undefined) {
@@ -59,7 +60,12 @@ export function parseTimeoutMsOrExit(timeout?: string): number | undefined | nul
   }
   const trimmed = timeout.trim();
   const seconds = Number(trimmed);
-  if (!/^\d+$/u.test(trimmed) || !Number.isSafeInteger(seconds) || seconds <= 0) {
+  if (
+    !/^\d+$/u.test(trimmed) ||
+    !Number.isSafeInteger(seconds) ||
+    seconds <= 0 ||
+    seconds > MAX_SAFE_TIMEOUT_SECONDS
+  ) {
     defaultRuntime.error(INVALID_TIMEOUT_ERROR);
     defaultRuntime.exit(1);
     return null;