diff --git a/zerver/webhooks/alertmanager/view.py b/zerver/webhooks/alertmanager/view.py
index d8a2de8dc6..2c3f14506c 100644
--- a/zerver/webhooks/alertmanager/view.py
+++ b/zerver/webhooks/alertmanager/view.py
@@ -1,11 +1,12 @@
 # Webhooks for external integrations.
-from typing import Any, Dict, List
+from typing import Dict, List
 
 from django.http import HttpRequest, HttpResponse
 
 from zerver.decorator import webhook_view
 from zerver.lib.request import REQ, has_request_variables
 from zerver.lib.response import json_success
+from zerver.lib.validator import WildValue, check_string, to_wild_value
 from zerver.lib.webhooks.common import check_send_webhook_message
 from zerver.models import UserProfile
 
@@ -15,7 +16,7 @@ from zerver.models import UserProfile
 def api_alertmanager_webhook(
     request: HttpRequest,
     user_profile: UserProfile,
-    payload: Dict[str, Any] = REQ(argument_type="body"),
+    payload: WildValue = REQ(argument_type="body", converter=to_wild_value),
     name_field: str = REQ("name", default="instance"),
     desc_field: str = REQ("desc", default="alertname"),
 ) -> HttpResponse:
@@ -25,15 +26,17 @@ def api_alertmanager_webhook(
         labels = alert.get("labels", {})
         annotations = alert.get("annotations", {})
 
-        name = labels.get(name_field, annotations.get(name_field, "(unknown)"))
-        desc = labels.get(desc_field, annotations.get(desc_field, f"<missing field: {desc_field}>"))
+        name = labels.get(name_field, annotations.get(name_field, "(unknown)")).tame(check_string)
+        desc = labels.get(
+            desc_field, annotations.get(desc_field, f"<missing field: {desc_field}>")
+        ).tame(check_string)
 
-        url = alert.get("generatorURL").replace("tab=1", "tab=0")
+        url = alert["generatorURL"].tame(check_string).replace("tab=1", "tab=0")
 
         body = f"{desc} ([graph]({url}))"
         if name not in topics:
             topics[name] = {"firing": [], "resolved": []}
-        topics[name][alert["status"]].append(body)
+        topics[name][alert["status"].tame(check_string)].append(body)
 
     for topic, statuses in topics.items():
         for status, messages in statuses.items():