diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index 7ebfa399813..dbc88cff171 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -29,17 +29,17 @@ jobs:
         uses: actions/checkout@v7
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4.38.1
+        uses: github/codeql-action/init@v4.38.2
         with:
           languages: ${{ matrix.language }}
           config-file: ./.github/codeql.yml
           queries: +security-and-quality
 
       - name: Autobuild
-        uses: github/codeql-action/autobuild@v4.38.1
+        uses: github/codeql-action/autobuild@v4.38.2
         if: ${{ matrix.language == 'python' || matrix.language == 'javascript' }}
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@v4.38.1
+        uses: github/codeql-action/analyze@v4.38.2
         with:
           category: "/language:${{ matrix.language }}"
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 3962f573c2e..b98f269a334 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -104,7 +104,7 @@ repos:
   - id: pyupgrade
     args: ['--py37-plus']
 - repo: https://github.com/PyCQA/flake8
-  rev: '7.3.0'
+  rev: '7.4.1'
   hooks:
   - id: flake8
     additional_dependencies:
diff --git a/CHANGES/13758.bugfix.rst b/CHANGES/13758.bugfix.rst
new file mode 100644
index 00000000000..36bb4ffc3e9
--- /dev/null
+++ b/CHANGES/13758.bugfix.rst
@@ -0,0 +1,6 @@
+Fixed a crash in :meth:`~aiohttp.BodyPartReader.read_chunk` on a body part
+with an explicit ``Content-Length: 0``: the part fell through to the
+streaming read strategy, whose minimum chunk size assertion then failed for
+chunk sizes below the boundary length. Such parts now yield an immediate
+empty chunk, like any other part with a known length
+-- by :user:`istoolsfox`.
diff --git a/CHANGES/13760.bugfix.rst b/CHANGES/13760.bugfix.rst
new file mode 120000
index 00000000000..4c97bb5bc7a
--- /dev/null
+++ b/CHANGES/13760.bugfix.rst
@@ -0,0 +1 @@
+13758.bugfix.rst
\ No newline at end of file
diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index e9e72254437..ddbd02c152d 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -188,6 +188,7 @@ Illia Volochii
 Ilya Chichak
 Ilya Gruzinov
 Ingmar Steen
+istoolsfox
 Ivan Lakovic
 Ivan Larin
 J. Nick Koston
diff --git a/aiohttp/multipart.py b/aiohttp/multipart.py
index 37895666d2d..957b21058d6 100644
--- a/aiohttp/multipart.py
+++ b/aiohttp/multipart.py
@@ -386,7 +386,7 @@ async def read_chunk(self, size: int = chunk_size) -> bytes:
         if carry:
             self._b64_carry = b""
             want = max(want, self._boundary_len)
-        if self._length:
+        if self._length is not None:
             fresh = await self._read_chunk_from_length(want)
         else:
             fresh = await self._read_chunk_from_stream(want)
diff --git a/requirements/constraints.txt b/requirements/constraints.txt
index 5a0fff5255a..36697d2bb0a 100644
--- a/requirements/constraints.txt
+++ b/requirements/constraints.txt
@@ -168,7 +168,7 @@ pip-tools==7.6.1
     # via -r requirements/dev.in
 pkgconfig==1.6.0
     # via -r requirements/test-common-base.in
-platformdirs==4.11.12
+platformdirs==4.11.14
     # via virtualenv
 pluggy==1.6.0
     # via
@@ -336,7 +336,7 @@ uvloop==0.22.1 ; platform_system != "Windows"
     #   -r requirements/lint.in
 valkey==6.1.1
     # via -r requirements/lint.in
-virtualenv==21.9.1
+virtualenv==21.12.1
     # via pre-commit
 wheel==0.48.0
     # via pip-tools
diff --git a/requirements/dev.txt b/requirements/dev.txt
index e6cfed71ab9..af815b6717e 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -165,7 +165,7 @@ pip-tools==7.6.1
     # via -r requirements/dev.in
 pkgconfig==1.6.0
     # via -r requirements/test-common-base.in
-platformdirs==4.11.12
+platformdirs==4.11.14
     # via virtualenv
 pluggy==1.6.0
     # via
@@ -326,7 +326,7 @@ uvloop==0.22.1 ; platform_system != "Windows" and implementation_name == "cpytho
     #   -r requirements/lint.in
 valkey==6.1.1
     # via -r requirements/lint.in
-virtualenv==21.9.1
+virtualenv==21.12.1
     # via pre-commit
 wheel==0.48.0
     # via pip-tools
diff --git a/requirements/lint.txt b/requirements/lint.txt
index d6b73071913..681fd47cd0d 100644
--- a/requirements/lint.txt
+++ b/requirements/lint.txt
@@ -86,7 +86,7 @@ packaging==26.3
     # via pytest
 pathspec==1.1.1
     # via mypy
-platformdirs==4.11.12
+platformdirs==4.11.14
     # via virtualenv
 pluggy==1.6.0
     # via pytest
@@ -166,7 +166,7 @@ uvloop==0.22.1 ; platform_system != "Windows"
     # via -r requirements/lint.in
 valkey==6.1.1
     # via -r requirements/lint.in
-virtualenv==21.9.1
+virtualenv==21.12.1
     # via pre-commit
 yarl==1.25.1
     # via aiohttp
diff --git a/tests/test_multipart.py b/tests/test_multipart.py
index 184b766f5f4..990175d89cd 100644
--- a/tests/test_multipart.py
+++ b/tests/test_multipart.py
@@ -206,6 +206,14 @@ async def test_read_chunk_without_content_length(self) -> None:
         assert c1 + c2 == b"Hello, world!"
         assert c3 == b""
 
+    async def test_read_chunk_with_zero_content_length(self) -> None:
+        with Stream(b"\r\n--:--\r\n") as stream:
+            d = HeadersDictProxy(CIMultiDict({"Content-Length": "0"}))
+            obj = aiohttp.BodyPartReader(BOUNDARY, d, stream)
+            result = await obj.read_chunk(4)
+            assert obj.at_eof()
+        assert b"" == result
+
     async def test_read_incomplete_chunk(self) -> None:
         with Stream(b"") as stream: