diff --git a/pyproject.toml b/pyproject.toml
index 002ee663..8f00af75 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -58,7 +58,7 @@ dependencies = [
     "svg2rlg~=0.3",
     "tini~=3.0.1",
     "tornado~=6.3",
-    "urllib3~=1.26.19",
+    "urllib3~=2.6.3",
     "whitenoise~=5.2.0",
     "yolk~=0.4.3",
     "zipp~=3.4.0",
diff --git a/uv.lock b/uv.lock
index 3d9a57a2..6bf6c1a3 100644
--- a/uv.lock
+++ b/uv.lock
@@ -984,7 +984,7 @@ requires-dist = [
     { name = "svg2rlg", specifier = "~=0.3" },
     { name = "tini", specifier = "~=3.0.1" },
     { name = "tornado", specifier = "~=6.3" },
-    { name = "urllib3", specifier = "~=1.26.19" },
+    { name = "urllib3", specifier = "~=2.6.3" },
     { name = "whitenoise", specifier = "~=5.2.0" },
     { name = "yolk", specifier = "~=0.4.3" },
     { name = "z3c-rml" },
@@ -1449,11 +1449,11 @@ wheels = [
 
 [[package]]
 name = "urllib3"
-version = "1.26.20"
+version = "2.6.3"
 source = { registry = "https://pypi.org/simple" }
-sdist = { url = "https://files.pythonhosted.org/packages/e4/e8/6ff5e6bc22095cfc59b6ea711b687e2b7ed4bdb373f7eeec370a97d7392f/urllib3-1.26.20.tar.gz", hash = "sha256:40c2dc0c681e47eb8f90e7e27bf6ff7df2e677421fd46756da1161c39ca70d32", size = 307380, upload-time = "2024-08-29T15:43:11.37Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/c7/24/5f1b3bdffd70275f6661c76461e25f024d5a38a46f04aaca912426a2b1d3/urllib3-2.6.3.tar.gz", hash = "sha256:1b62b6884944a57dbe321509ab94fd4d3b307075e0c2eae991ac71ee15ad38ed", size = 435556, upload-time = "2026-01-07T16:24:43.925Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/33/cf/8435d5a7159e2a9c83a95896ed596f68cf798005fe107cc655b5c5c14704/urllib3-1.26.20-py2.py3-none-any.whl", hash = "sha256:0ed14ccfbf1c30a9072c7ca157e4319b70d65f623e91e7b32fadb2853431016e", size = 144225, upload-time = "2024-08-29T15:43:08.921Z" },
+    { url = "https://files.pythonhosted.org/packages/39/08/aaaad47bc4e9dc8c725e68f9d04865dbcb2052843ff09c97b08904852d84/urllib3-2.6.3-py3-none-any.whl", hash = "sha256:bf272323e553dfb2e87d9bfd225ca7b0f467b919d7bbd355436d3fd37cb0acd4", size = 131584, upload-time = "2026-01-07T16:24:42.685Z" },
 ]
 
 [package.optional-dependencies]