diff --git a/Dockerfile b/Dockerfile
index 0b92e95..9f2762b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 # Stage 1: Build
 FROM node:20-alpine AS build
-
+RUN apk update && apk upgrade --no-cache
 WORKDIR /app
 
 COPY package.json package-lock.json ./
@@ -11,6 +11,9 @@ RUN npm run build
 
 # Stage 2: Production — uses nginxinc/nginx-unprivileged which runs as non-root (UID 101)
 FROM nginxinc/nginx-unprivileged:stable-alpine AS prod
+USER root
+RUN apk update && apk upgrade --no-cache
+USER 101
 
 COPY --from=build /app/dist /usr/share/nginx/html
 COPY nginx.conf /etc/nginx/conf.d/default.conf
diff --git a/api/Dockerfile b/api/Dockerfile
index e3b4bbf..771d5ec 100644
--- a/api/Dockerfile
+++ b/api/Dockerfile
@@ -1,6 +1,6 @@
 FROM python:3.12-slim AS build
 
-RUN apt-get update && apt-get install -y --no-install-recommends \
+RUN apt-get update && apt-get upgrade -y && apt-get install -y --no-install-recommends \
     libpq-dev \
     build-essential \
     && rm -rf /var/lib/apt/lists/*
@@ -12,7 +12,7 @@ RUN pip install --no-cache-dir --prefix=/install .
 
 FROM python:3.12-slim AS prod
 
-RUN apt-get update && apt-get install -y --no-install-recommends libpq5 && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && apt-get upgrade -y && apt-get install -y --no-install-recommends libpq5 && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /app
 RUN adduser --system --group --uid 1000 app
diff --git a/auth/Dockerfile b/auth/Dockerfile
index 1028e89..0b88089 100644
--- a/auth/Dockerfile
+++ b/auth/Dockerfile
@@ -1,4 +1,5 @@
 FROM node:22-alpine AS builder
+RUN apk update && apk upgrade --no-cache
 WORKDIR /app
 COPY package.json package-lock.json* ./
 RUN npm ci
@@ -7,6 +8,7 @@ COPY src/ src/
 RUN npm run build
 
 FROM node:22-alpine
+RUN apk update && apk upgrade --no-cache
 WORKDIR /app
 ENV NODE_ENV=production
 COPY package.json package-lock.json* ./
diff --git a/auth/package-lock.json b/auth/package-lock.json
index 1f7bfc9..373abad 100644
--- a/auth/package-lock.json
+++ b/auth/package-lock.json
@@ -941,9 +941,9 @@
       }
     },
     "node_modules/defu": {
-      "version": "6.1.4",
-      "resolved": "https://registry.npmjs.org/defu/-/defu-6.1.4.tgz",
-      "integrity": "sha512-mEQCMmwJu317oSz8CwdIOdwf3xMif1ttiM8LTufzc3g6kR+9Pe236twL8j3IYT1F7GfRgGcW6MWxzZjLIkuHIg==",
+      "version": "6.1.7",
+      "resolved": "https://registry.npmjs.org/defu/-/defu-6.1.7.tgz",
+      "integrity": "sha512-7z22QmUWiQ/2d0KkdYmANbRUVABpZ9SNYyH5vx6PZ+nE5bcC0l7uFvEfHlyld/HcGBFTL536ClDt3DEcSlEJAQ==",
       "license": "MIT"
     },
     "node_modules/delegates": {
diff --git a/receiptwitness/Dockerfile b/receiptwitness/Dockerfile
index 8fead61..79e53a3 100644
--- a/receiptwitness/Dockerfile
+++ b/receiptwitness/Dockerfile
@@ -5,7 +5,7 @@ WORKDIR /app
 
 # build-essential and libpq-dev are needed to compile any C-extension wheels
 # (e.g. psycopg2 fallback).  No git needed — common/ is copied from the repo root.
-RUN apt-get update && apt-get install -y --no-install-recommends \
+RUN apt-get update && apt-get upgrade -y && apt-get install -y --no-install-recommends \
     libpq-dev \
     build-essential \
     && rm -rf /var/lib/apt/lists/*
@@ -25,7 +25,7 @@ FROM python:3.12-slim AS prod
 WORKDIR /app
 
 # Install Playwright system dependencies for Chromium
-RUN apt-get update && apt-get install -y --no-install-recommends \
+RUN apt-get update && apt-get upgrade -y && apt-get install -y --no-install-recommends \
     libnss3 \
     libatk1.0-0 \
     libatk-bridge2.0-0 \