diff --git a/hermes_cli/session_export_html.py b/hermes_cli/session_export_html.py
index 6b3821ed03e..2489cf653a7 100644
--- a/hermes_cli/session_export_html.py
+++ b/hermes_cli/session_export_html.py
@@ -706,7 +706,7 @@ def _generate_messages_html(messages: List[Dict[str, Any]]) -> str:
                 <div class="tool-call">
                     <div class="tool-call-header">
                         {ICON_CHEVRON_RIGHT.replace('class="', 'class="chevron ')}
-                        {ICON_WRENCH} Tool Call: {fn_name}
+                        {ICON_WRENCH} Tool Call: {_escape_html(fn_name)}
                     </div>
                     <div class="tool-call-content">
                         <pre><code>{_escape_html(args)}</code></pre>
diff --git a/tests/hermes_cli/test_session_export_html.py b/tests/hermes_cli/test_session_export_html.py
new file mode 100644
index 00000000000..cadfb6e19a1
--- /dev/null
+++ b/tests/hermes_cli/test_session_export_html.py
@@ -0,0 +1,60 @@
+"""Tests for the HTML session export renderer."""
+
+from hermes_cli.session_export_html import (
+    _generate_messages_html,
+    generate_multi_session_html_export,
+)
+
+
+def test_tool_call_name_is_escaped():
+    """A tool-call name is attacker-influenced (a prompt-injected model can emit
+    an arbitrary name), so it must be HTML-escaped like every sibling field."""
+    payload = '<img src=x onerror="alert(1)">'
+    html = _generate_messages_html([
+        {
+            "role": "assistant",
+            "content": "",
+            "tool_calls": [
+                {
+                    "id": "call_1",
+                    "type": "function",
+                    "function": {"name": payload, "arguments": "{}"},
+                }
+            ],
+        }
+    ])
+    assert payload not in html
+    assert "&lt;img src=x onerror=" in html
+
+
+def test_tool_call_arguments_stay_escaped():
+    html = _generate_messages_html([
+        {
+            "role": "assistant",
+            "content": "",
+            "tool_calls": [
+                {
+                    "id": "call_1",
+                    "type": "function",
+                    "function": {"name": "terminal", "arguments": "<b>x</b>"},
+                }
+            ],
+        }
+    ])
+    assert "&lt;b&gt;x&lt;/b&gt;" in html
+    assert "<b>x</b>" not in html
+
+
+def test_multi_session_export_keeps_switcher_script():
+    """The multi-session export drives session switching with an inline script,
+    so the escaping fix must not remove or block that script."""
+    sessions = [
+        {"id": "aaaa1111", "title": "First", "started_at": 0,
+         "messages": [{"role": "user", "content": "one"}]},
+        {"id": "bbbb2222", "title": "Second", "started_at": 0,
+         "messages": [{"role": "user", "content": "two"}]},
+    ]
+    html = generate_multi_session_html_export(sessions)
+    assert "function showSession" in html
+    assert 'data-id="aaaa1111"' in html
+    assert 'id="view-bbbb2222"' in html