diff --git a/.github/workflows/crowdin_upload.yml b/.github/workflows/crowdin_upload.yml
index 9ffb383b..0dbfa57a 100644
--- a/.github/workflows/crowdin_upload.yml
+++ b/.github/workflows/crowdin_upload.yml
@@ -25,7 +25,7 @@ jobs:
       - name: Install Python
         uses: actions/setup-python@v3
         with:
-          python-version: "3.12.6"
+          python-version: "3.13.3"
       - name: Upgrade pip and setuptools
         run: pip install --upgrade pip setuptools
       - name: Install development dependencies
diff --git a/.github/workflows/impress.yml b/.github/workflows/impress.yml
index 0db5b2fd..02b4ce88 100644
--- a/.github/workflows/impress.yml
+++ b/.github/workflows/impress.yml
@@ -91,7 +91,7 @@ jobs:
       - name: Install Python
         uses: actions/setup-python@v3
         with:
-          python-version: "3.12.6"
+          python-version: "3.13.3"
       - name: Upgrade pip and setuptools
         run: pip install --upgrade pip setuptools
       - name: Install development dependencies
@@ -186,7 +186,7 @@ jobs:
       - name: Install Python
         uses: actions/setup-python@v3
         with:
-          python-version: "3.12.6"
+          python-version: "3.13.3"
 
       - name: Install development dependencies
         run: pip install --user .[dev]
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e7b2898e..fd61c38f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,8 @@ and this project adheres to
 
 - 📝(frontend) Update documentation
 - ✅(frontend) Improve tests coverage
+- ⬆️(docker) upgrade backend image to python 3.13 #973
+
 
 ### Removed
 
diff --git a/Dockerfile b/Dockerfile
index 23f26b70..37c76034 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,7 +1,7 @@
 # Django impress
 
 # ---- base image to inherit from ----
-FROM python:3.12.6-alpine3.20 AS base
+FROM python:3.13.3-alpine AS base
 
 # Upgrade pip to its latest release to speed up dependencies installation
 RUN python -m pip install --upgrade pip setuptools
@@ -30,7 +30,7 @@ RUN mkdir /install && \
 
 
 # ---- mails ----
-FROM node:20 AS mail-builder
+FROM node:24 AS mail-builder
 
 COPY ./src/mail /mail/app
 
@@ -139,6 +139,9 @@ CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]
 # ---- Production image ----
 FROM core AS backend-production
 
+# Remove apk cache, we don't need it anymore
+RUN rm -rf /var/cache/apk/*
+
 ARG IMPRESS_STATIC_ROOT=/data/static
 
 # Gunicorn
diff --git a/src/backend/core/tests/documents/test_api_documents_attachment_upload.py b/src/backend/core/tests/documents/test_api_documents_attachment_upload.py
index 214a1a2b..94fd9771 100644
--- a/src/backend/core/tests/documents/test_api_documents_attachment_upload.py
+++ b/src/backend/core/tests/documents/test_api_documents_attachment_upload.py
@@ -410,5 +410,9 @@ def test_api_documents_attachment_upload_unsafe():
         "is_unsafe": "true",
         "status": "processing",
     }
-    assert file_head["ContentType"] == "application/octet-stream"
+    # Depending the libmagic version, the content type may change.
+    assert file_head["ContentType"] in [
+        "application/x-dosexec",
+        "application/octet-stream",
+    ]
     assert file_head["ContentDisposition"] == 'attachment; filename="script.exe"'