diff --git a/esphome/components/web_server_idf/web_server_idf.cpp b/esphome/components/web_server_idf/web_server_idf.cpp
index 2e07fb6e0a..d7d6f90355 100644
--- a/esphome/components/web_server_idf/web_server_idf.cpp
+++ b/esphome/components/web_server_idf/web_server_idf.cpp
@@ -881,12 +881,12 @@ esp_err_t AsyncWebServer::handle_multipart_upload_(httpd_req_t *r, const char *c
     }
   });
 
-  // Process data - use stack buffer to avoid heap allocation
-  char buffer[MULTIPART_CHUNK_SIZE];
+  // Use heap buffer - 1460 bytes is too large for the httpd task stack
+  auto buffer = std::make_unique<char[]>(MULTIPART_CHUNK_SIZE);
   size_t bytes_since_yield = 0;
 
   for (size_t remaining = r->content_len; remaining > 0;) {
-    int recv_len = httpd_req_recv(r, buffer, std::min(remaining, MULTIPART_CHUNK_SIZE));
+    int recv_len = httpd_req_recv(r, buffer.get(), std::min(remaining, MULTIPART_CHUNK_SIZE));
 
     if (recv_len <= 0) {
       httpd_resp_send_err(r, recv_len == HTTPD_SOCK_ERR_TIMEOUT ? HTTPD_408_REQ_TIMEOUT : HTTPD_400_BAD_REQUEST,
@@ -894,7 +894,7 @@ esp_err_t AsyncWebServer::handle_multipart_upload_(httpd_req_t *r, const char *c
       return recv_len == HTTPD_SOCK_ERR_TIMEOUT ? ESP_ERR_TIMEOUT : ESP_FAIL;
     }
 
-    if (reader->parse(buffer, recv_len) != static_cast<size_t>(recv_len)) {
+    if (reader->parse(buffer.get(), recv_len) != static_cast<size_t>(recv_len)) {
       ESP_LOGW(TAG, "Multipart parser error");
       httpd_resp_send_err(r, HTTPD_400_BAD_REQUEST, nullptr);
       return ESP_FAIL;