diff --git a/.chronus/changes/update-python-setuptools-2026-8-5.md b/.chronus/changes/update-python-setuptools-2026-8-5.md
new file mode 100644
index 00000000000..ac116dd827e
--- /dev/null
+++ b/.chronus/changes/update-python-setuptools-2026-8-5.md
@@ -0,0 +1,7 @@
+---
+changeKind: dependencies
+packages:
+  - "@typespec/http-client-python"
+---
+
+Update setuptools to 83.0.0 to address CVE-2026-59890.
diff --git a/packages/http-client-python/generator/pygen/codegen/templates/packaging_templates/pyproject.toml.jinja2 b/packages/http-client-python/generator/pygen/codegen/templates/packaging_templates/pyproject.toml.jinja2
index 68915429341..5f63b5a2a03 100644
--- a/packages/http-client-python/generator/pygen/codegen/templates/packaging_templates/pyproject.toml.jinja2
+++ b/packages/http-client-python/generator/pygen/codegen/templates/packaging_templates/pyproject.toml.jinja2
@@ -5,7 +5,7 @@
 {% endif %}
 
 [build-system]
-requires = ["setuptools>=77.0.3", "wheel"]
+requires = ["setuptools>=83.0.0", "wheel"]
 build-backend = "setuptools.build_meta"
 
 [project]
diff --git a/packages/http-client-python/generator/setup.py b/packages/http-client-python/generator/setup.py
index cb08938e73d..a2e69410646 100644
--- a/packages/http-client-python/generator/setup.py
+++ b/packages/http-client-python/generator/setup.py
@@ -52,6 +52,6 @@
         "Jinja2==3.1.6",
         "PyYAML==6.0.1",
         "tomli==2.0.1",
-        "setuptools==75.3.2",
+        "setuptools==83.0.0",
     ],
 )
diff --git a/packages/http-client-python/tests/generated/azure/authentication-union/pyproject.toml b/packages/http-client-python/tests/generated/azure/authentication-union/pyproject.toml
index c31cd4a1a76..58165878495 100644
--- a/packages/http-client-python/tests/generated/azure/authentication-union/pyproject.toml
+++ b/packages/http-client-python/tests/generated/azure/authentication-union/pyproject.toml
@@ -6,7 +6,7 @@
 # --------------------------------------------------------------------------
 
 [build-system]
-requires = ["setuptools>=77.0.3", "wheel"]
+requires = ["setuptools>=83.0.0", "wheel"]
 build-backend = "setuptools.build_meta"
 
 [project]
diff --git a/packages/http-client-python/tests/unit/test_pyproject_keep_fields.py b/packages/http-client-python/tests/unit/test_pyproject_keep_fields.py
index b58c4ef6000..a74ecbabf9f 100644
--- a/packages/http-client-python/tests/unit/test_pyproject_keep_fields.py
+++ b/packages/http-client-python/tests/unit/test_pyproject_keep_fields.py
@@ -213,6 +213,11 @@ def _render_pyproject(option_value, existing_content):
 """
 
 
+def test_render_requires_patched_setuptools():
+    parsed = _render_pyproject("", _EXISTING)
+    assert parsed["build-system"]["requires"] == ["setuptools>=83.0.0", "wheel"]
+
+
 def test_render_keeps_selected_fields():
     parsed = _render_pyproject("authors,description", _EXISTING)["project"]
     # Selected fields are preserved from the existing file.