diff --git a/rdagent/scenarios/rl/autorl_bench/benchmarks/webshop/requirements.txt b/rdagent/scenarios/rl/autorl_bench/benchmarks/webshop/requirements.txt
index 781773ce..7ec6e794 100644
--- a/rdagent/scenarios/rl/autorl_bench/benchmarks/webshop/requirements.txt
+++ b/rdagent/scenarios/rl/autorl_bench/benchmarks/webshop/requirements.txt
@@ -28,11 +28,12 @@ spacy==3.7.2
 # Security: Upgrade Werkzeug/Flask AFTER webshop to override transitive dependencies
 # webshop 0.1.0 depends on Werkzeug 2.2.3, but we force upgrade to 3.1.6+
 # Security Notes:
+# - CVE-2026-27205: Vary: Cookie header not set in some cases (fixed in 3.1.3)
 # - CVE-2026-27199: Windows device names in safe_join() (fixed in 3.1.6)
 # - CVE-2025-66221: Windows device names in safe_join() (fixed in 3.1.4)
 # - CVE-2024-49766: safe_join UNC path bypass on Windows (fixed in 3.0.6)
 # - CVE-2024-34069: Werkzeug debugger RCE (fixed in 3.0.3+)
 # - CVE-2024-49767: Resource exhaustion via multipart/form-data (fixed)
 # - CVE-2023-46136: DoS via multipart/form-data parser (fixed in 2.3.8+)
-flask>=3.1.0  # Override webshop's Flask 2.2.5 dependency
+flask>=3.1.3  # Override webshop's Flask 2.2.5 dependency - fixes CVE-2026-27205
 Werkzeug>=3.1.6  # Override webshop's Werkzeug 2.2.3 dependency - fixes all CVEs
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