From c1fb8dae37a3ee137a442de424ea67243e32e793 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Wed, 12 Nov 2025 10:33:19 -0600
Subject: [PATCH] [light] Fix dangling reference in compute_color_mode causing
 memory corruption

---
 esphome/components/light/light_call.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/esphome/components/light/light_call.cpp b/esphome/components/light/light_call.cpp
index df17f53adc..b81ecc57cb 100644
--- a/esphome/components/light/light_call.cpp
+++ b/esphome/components/light/light_call.cpp
@@ -406,7 +406,11 @@ void LightCall::transform_parameters_() {
   }
 }
 ColorMode LightCall::compute_color_mode_() {
-  const auto &supported_modes = this->parent_->get_traits().get_supported_color_modes();
+  // Store traits locally to avoid dangling reference: get_traits() returns by value, so
+  // calling get_traits().get_supported_color_modes() would create a temporary LightTraits
+  // object, return a reference to its member, then destroy the temporary, leaving a dangling reference.
+  auto traits = this->parent_->get_traits();
+  const auto &supported_modes = traits.get_supported_color_modes();
   int supported_count = supported_modes.size();
 
   // Some lights don't support any color modes (e.g. monochromatic light), leave it at unknown.