diff --git a/backend/pyproject.toml b/backend/pyproject.toml
index 1b74a77c4..6d2edb0bb 100644
--- a/backend/pyproject.toml
+++ b/backend/pyproject.toml
@@ -8,7 +8,7 @@ dependencies = [
     "deerflow-harness",
     "fastapi>=0.115.0",
     "httpx>=0.28.0",
-    "python-multipart>=0.0.26",
+    "python-multipart>=0.0.27",
     "sse-starlette>=2.1.0",
     "uvicorn[standard]>=0.34.0",
     "lark-oapi>=1.4.0",
diff --git a/backend/uv.lock b/backend/uv.lock
index 822b1ac93..6860249c6 100644
--- a/backend/uv.lock
+++ b/backend/uv.lock
@@ -788,7 +788,7 @@ requires-dist = [
     { name = "lark-oapi", specifier = ">=1.4.0" },
     { name = "markdown-to-mrkdwn", specifier = ">=0.3.1" },
     { name = "pyjwt", specifier = ">=2.9.0" },
-    { name = "python-multipart", specifier = ">=0.0.26" },
+    { name = "python-multipart", specifier = ">=0.0.27" },
     { name = "python-telegram-bot", specifier = ">=21.0" },
     { name = "slack-sdk", specifier = ">=3.33.0" },
     { name = "sse-starlette", specifier = ">=2.1.0" },
@@ -3532,11 +3532,11 @@ wheels = [
 
 [[package]]
 name = "python-multipart"
-version = "0.0.26"
+version = "0.0.27"
 source = { registry = "https://pypi.org/simple" }
-sdist = { url = "https://files.pythonhosted.org/packages/88/71/b145a380824a960ebd60e1014256dbb7d2253f2316ff2d73dfd8928ec2c3/python_multipart-0.0.26.tar.gz", hash = "sha256:08fadc45918cd615e26846437f50c5d6d23304da32c341f289a617127b081f17", size = 43501, upload-time = "2026-04-10T14:09:59.473Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/69/9b/f23807317a113dc36e74e75eb265a02dd1a4d9082abc3c1064acd22997c4/python_multipart-0.0.27.tar.gz", hash = "sha256:9870a6a8c5a20a5bf4f07c017bd1489006ff8836cff097b6933355ee2b49b602", size = 44043, upload-time = "2026-04-27T10:51:26.649Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/9a/22/f1925cdda983ab66fc8ec6ec8014b959262747e58bdca26a4e3d1da29d56/python_multipart-0.0.26-py3-none-any.whl", hash = "sha256:c0b169f8c4484c13b0dcf2ef0ec3a4adb255c4b7d18d8e420477d2b1dd03f185", size = 28847, upload-time = "2026-04-10T14:09:58.131Z" },
+    { url = "https://files.pythonhosted.org/packages/99/78/4126abcbdbd3c559d43e0db7f7b9173fc6befe45d39a2856cc0b8ec2a5a6/python_multipart-0.0.27-py3-none-any.whl", hash = "sha256:6fccfad17a27334bd0193681b369f476eda3409f17381a2d65aa7df3f7275645", size = 29254, upload-time = "2026-04-27T10:51:24.997Z" },
 ]
 
 [[package]]