diff --git a/litellm/llms/xai/oauth.py b/litellm/llms/xai/oauth.py
index 2533f7a9aae..a9455a5d07d 100644
--- a/litellm/llms/xai/oauth.py
+++ b/litellm/llms/xai/oauth.py
@@ -258,7 +258,12 @@ class XAIOAuthAuthenticator:
             raise XAIOAuthError(
                 f"xAI OAuth discovery request failed: {exc.response.status_code} {exc.response.text}"
             ) from exc
-        data = response.json()
+        try:
+            data = response.json()
+        except ValueError as exc:
+            raise XAIOAuthError(
+                "xAI OAuth discovery response was not valid JSON"
+            ) from exc
         authorization_endpoint = data.get("authorization_endpoint")
         token_endpoint = data.get("token_endpoint")
         if not authorization_endpoint or not token_endpoint:
@@ -355,7 +360,10 @@ class XAIOAuthAuthenticator:
             raise XAIOAuthError(
                 f"xAI OAuth token request failed: {exc.response.status_code} {exc.response.text}"
             ) from exc
-        body = response.json()
+        try:
+            body = response.json()
+        except ValueError as exc:
+            raise XAIOAuthError("xAI OAuth token response was not valid JSON") from exc
         if not isinstance(body, dict):
             raise XAIOAuthError("xAI OAuth token response was not an object")
         return body
diff --git a/tests/test_litellm/llms/xai/test_xai_oauth.py b/tests/test_litellm/llms/xai/test_xai_oauth.py
index c88f8de7525..c410d2ea502 100644
--- a/tests/test_litellm/llms/xai/test_xai_oauth.py
+++ b/tests/test_litellm/llms/xai/test_xai_oauth.py
@@ -287,6 +287,19 @@ def test_discover_wraps_http_errors():
     )
 
 
+def test_discover_wraps_invalid_json_response():
+    authenticator = XAIOAuthAuthenticator(
+        http_client=httpx.Client(
+            transport=httpx.MockTransport(
+                lambda request: httpx.Response(200, text="<html>not-json</html>")
+            )
+        )
+    )
+
+    with pytest.raises(XAIOAuthError, match="discovery response was not valid JSON"):
+        authenticator._discover()
+
+
 def test_refresh_discovers_token_endpoint_when_auth_file_is_legacy(
     tmp_path, monkeypatch
 ):
@@ -340,6 +353,19 @@ def test_exchange_token_rejects_non_object_response():
         authenticator._exchange_token("https://auth.x.ai/oauth/token", {})
 
 
+def test_exchange_token_wraps_invalid_json_response():
+    authenticator = XAIOAuthAuthenticator(
+        http_client=httpx.Client(
+            transport=httpx.MockTransport(
+                lambda request: httpx.Response(200, text="<html>not-json</html>")
+            )
+        )
+    )
+
+    with pytest.raises(XAIOAuthError, match="token response was not valid JSON"):
+        authenticator._exchange_token("https://auth.x.ai/oauth/token", {})
+
+
 def test_start_callback_server_falls_back_to_ephemeral_port(monkeypatch):
     calls = []
     real_server = xai_oauth_module._CallbackServer