diff --git a/homeassistant/package_constraints.txt b/homeassistant/package_constraints.txt
index 2135a47d4db..8cf3927516f 100644
--- a/homeassistant/package_constraints.txt
+++ b/homeassistant/package_constraints.txt
@@ -129,6 +129,9 @@ multidict>=6.0.2
 # Version 2.0 added typing, prevent accidental fallbacks
 backoff>=2.0
 
+# Brotli 1.2.0 fixes CVE and is required for aiohttp 3.13.3 compatibility
+Brotli>=1.2.0
+
 # ensure pydantic version does not float since it might have breaking changes
 pydantic==2.12.2
 
diff --git a/script/gen_requirements_all.py b/script/gen_requirements_all.py
index 29c0e835b26..0f542aeb1bb 100755
--- a/script/gen_requirements_all.py
+++ b/script/gen_requirements_all.py
@@ -120,6 +120,9 @@ multidict>=6.0.2
 # Version 2.0 added typing, prevent accidental fallbacks
 backoff>=2.0
 
+# Brotli 1.2.0 fixes CVE and is required for aiohttp 3.13.3 compatibility
+Brotli>=1.2.0
+
 # ensure pydantic version does not float since it might have breaking changes
 pydantic==2.12.2