diff --git a/collabora/CHANGELOG.md b/collabora/CHANGELOG.md
index 116a541546..6792738832 100644
--- a/collabora/CHANGELOG.md
+++ b/collabora/CHANGELOG.md
@@ -1,4 +1,19 @@
  
+## 26.04.2.4.1 (2026-07-26)
+- Rebuild on a Debian base: upstream turned collabora/code into a distroless image with no shell, which broke the addon build entirely. collabora/code stays the tracked upstream image in build.json, but is now a build stage whose payload is copied onto ghcr.io/hassio-addons/debian-base, and the addon ships its own launcher in place of the removed /start-collabora-online.sh
+- build.json names the architecture explicitly again (`collabora/code:latest-amd64` and `collabora/code:latest-arm64`). The builder never passes `--platform`, so the tag is the only thing that decides which binaries land in the addon
+- Restore the file capabilities on `coolforkit-caps` and `coolmount`. The official image carries them as extended attributes, which `COPY --from` does not transfer, and without them Collabora starts but cannot open any document
+- The certificates for `ssl: true` are read from the copies in /etc/coolwsd rather than from /ssl directly, which Collabora could not read as uid 1001 when the private key is root-only
+- Make the `ssl` option authoritative even when `extra_params` is empty or customized. `ssl: false` now always disables Collabora's internal HTTPS instead of silently falling back to its default self-signed TLS
+- Fix version numbering: releases on CollaboraOnline/online are now Helm charts only, which had renumbered the addon from 25.4.9.2 down to 1.3.0 and hid updates. The version is tracked from the collabora/code Docker Hub tags again
+- `server_name` is now passed to Collabora, fixing `Your browser has been unable to connect to the Collabora server` behind a reverse proxy
+- `domain1` was never passed to Collabora at all (the script read a `domain` option that does not exist, and recent Collabora releases dropped that variable). It is now deprecated and applied as `server_name`
+- `aliasgroup*` values are normalised: unescaped, escaped and double-escaped dots all produce the correct regex, and the value handed to Collabora is printed in the log
+- Added `ssl_termination`, needed when `ssl` is false but Collabora is reached over https through a reverse proxy
+- Added `aliasgroup2` and `aliasgroup3` for additional Nextcloud servers
+- `cert_domain` is now a string (it is a certificate common name) and is passed to Collabora
+- Documented the above, and corrected the README which asked for two backslashes where Collabora expects one
+ 
 ## 1.3.0 (2026-07-16)
 - Update to latest version from CollaboraOnline/online (changelog : https://github.com/CollaboraOnline/online/releases)
  
diff --git a/collabora/Dockerfile b/collabora/Dockerfile
index e6a80949e9..a14f258332 100644
--- a/collabora/Dockerfile
+++ b/collabora/Dockerfile
@@ -16,7 +16,45 @@
 
 ARG BUILD_FROM
 ARG BUILD_VERSION
-FROM ${BUILD_FROM}
+
+###############################################################################
+# Get Collabora Online from the official image (BUILD_FROM, see build.json)
+#
+# build.json pins the architecture explicitly, collabora/code:latest-amd64 and
+# collabora/code:latest-arm64, rather than the multi-arch collabora/code:latest.
+# The builder never passes --platform: it runs the amd64 build on a native amd64
+# runner and the aarch64 build on a native arm runner, so the only thing that
+# decides which Collabora binaries end up in the add-on is this tag. With the
+# multi-arch tag that happens to resolve correctly, but only for as long as the
+# runner architecture keeps matching the target, and a mismatch would silently
+# produce an image full of foreign-architecture binaries. The per-arch tags are
+# published in lockstep with latest, so nothing is lost by naming them.
+#
+# Upstream rebuilt collabora/code as a Nix-based distroless image: /bin and
+# /sbin are empty, so it can no longer be the base of the add-on itself, as s6,
+# bashio and every RUN need a shell. It stays the tracked upstream image, and
+# only the Collabora payload is copied out of it onto a Debian runtime.
+#
+# Copy only what belongs to Collabora. Do NOT copy /etc or /nix: in that image
+# /etc/resolv.conf, /etc/hosts, /etc/passwd, /etc/group and /etc/nsswitch.conf
+# are symlinks into /nix/store, and importing them breaks DNS resolution and
+# wipes the base image users.
+###############################################################################
+# hadolint ignore=DL3006
+FROM ${BUILD_FROM} AS collabora
+
+###############################################################################
+# Build the actual add-on on a base that has a shell
+###############################################################################
+FROM ghcr.io/hassio-addons/debian-base:9.3.0
+
+# Inherited from the base, declared here so it is visible to hadolint and to
+# anyone adding a pipe below. Note that the linkage check does NOT pipe into
+# grep: with pipefail an ldd that exits non-zero (a binary it cannot handle at
+# all) would make the pipeline fail even though grep matched, and "if" would
+# then read that as "no unresolved libraries" -- the one case worth catching.
+# Capturing the output and matching it with case avoids the question entirely.
+SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 
 ##################
 # 2 Modify Image #
@@ -55,11 +93,88 @@ COPY ha_automodules.sh /ha_automodules.sh
 RUN chmod 744 /ha_automodules.sh && /ha_automodules.sh "$MODULES" && rm /ha_automodules.sh
 
 # Manual apps
-ENV PACKAGES=""
+# coolwsd itself only needs glibc/libstdc++ (max GLIBCXX_3.4.22); the office
+# engine bundles its own cairo, fontconfig, curl, icu and fonts under
+# /opt/collaboraoffice/program. openssl is used to generate the self-signed
+# certificate when the ssl option is off, cpio and findutils by the jail setup.
+ENV PACKAGES="ca-certificates cpio findutils fontconfig libcap2-bin libstdc++6 openssl tzdata"
 
 # Automatic apps & bashio
 COPY ha_autoapps.sh /ha_autoapps.sh
-RUN chmod 744 /ha_autoapps.sh && /ha_autoapps.sh "$PACKAGES" || true && rm /ha_autoapps.sh
+RUN chmod 744 /ha_autoapps.sh && /ha_autoapps.sh "$PACKAGES" && rm /ha_autoapps.sh
+
+# Collabora Online payload, taken from the official image. COPY --from keeps the
+# numeric ownership, so /opt/cool and /etc/coolwsd arrive already owned by 1001.
+COPY --from=collabora /usr/bin/coolwsd /usr/bin/coolforkit-caps /usr/bin/coolforkit-ns /usr/bin/coolmount /usr/bin/
+COPY --from=collabora /usr/share/coolwsd /usr/share/coolwsd
+COPY --from=collabora /etc/coolwsd /etc/coolwsd
+COPY --from=collabora /opt/collaboraoffice /opt/collaboraoffice
+COPY --from=collabora /opt/cool /opt/cool
+
+# Recreate the runtime user the official image declares (uid/gid 1001), and the
+# per-container state upstream sets up in its own final build stage.
+RUN \
+    groupadd --gid 1001 cool && \
+    useradd --uid 1001 --gid 1001 --no-create-home --home-dir /opt/cool --shell /usr/sbin/nologin cool && \
+    mkdir -p /opt/cool/child-roots /opt/cool/cache && \
+    chown -R 1001:1001 /opt/cool /etc/coolwsd && \
+    chmod 640 /etc/coolwsd/coolwsd.xml && \
+    touch /var/log/coolwsd.log && \
+    chown 1001:1001 /var/log/coolwsd.log && \
+    # the WOPI proof key must be unique per container, not baked into the image
+    rm -rf /etc/coolwsd/proof_key* && \
+    (fc-cache /opt/collaboraoffice/share/fonts/truetype > /dev/null 2>&1 || true)
+
+# Restore the file capabilities. The official image carries them as extended
+# attributes on two binaries:
+#   coolforkit-caps  cap_chown,cap_fowner,cap_sys_chroot=ep
+#   coolmount        cap_sys_admin=ep
+# COPY --from does not transfer extended attributes, so both arrive stripped.
+# Nothing about the build notices: coolwsd starts and serves the admin console,
+# but every document fails to open because it cannot chroot a kit process. Set
+# them again and check they stuck, so a builder without xattr support fails here
+# instead of shipping an add-on that only looks like it works.
+#
+# cap_sys_admin on coolmount only takes effect if the container is given
+# SYS_ADMIN, which the add-on does not request; without it Collabora copies its
+# child roots instead of bind-mounting them, which is slower but works.
+RUN \
+    setcap "cap_chown,cap_fowner,cap_sys_chroot=ep" /usr/bin/coolforkit-caps && \
+    setcap "cap_sys_admin=ep" /usr/bin/coolmount && \
+    caps="$(getcap /usr/bin/coolforkit-caps /usr/bin/coolmount)" && \
+    case "$caps" in \
+    *cap_sys_chroot*) ;; \
+    *) echo "coolforkit-caps lost its capabilities: ${caps}"; exit 1 ;; \
+    esac && \
+    case "$caps" in \
+    *cap_sys_admin*) ;; \
+    *) echo "coolmount lost its capabilities: ${caps}"; exit 1 ;; \
+    esac
+
+# Fail the build rather than ship an image with unresolved runtime dependencies.
+# The payload was linked against the libraries of the distroless image, so each
+# executable and shared library is checked against the Debian runtime.
+#
+# coolwsd itself cannot be executed as a smoke test. It refuses to run as root
+# ("Do not run as root. Please run as cool user.", exit 78), and --version does
+# not exit either -- the official entrypoint passes it to the long-running
+# server to get the version into the log. Checking that every binary resolves
+# its libraries proves the same thing and terminates.
+RUN \
+    command -v openssl > /dev/null && \
+    command -v su > /dev/null && \
+    for binary in \
+    /usr/bin/coolwsd \
+    /usr/bin/coolforkit-caps \
+    /usr/bin/coolforkit-ns \
+    /usr/bin/coolmount \
+    /opt/collaboraoffice/program/soffice.bin \
+    /opt/collaboraoffice/program/libmergedlo.so; do \
+    libs="$(ldd "$binary" 2>&1)"; \
+    case "$libs" in \
+    *"not found"*) echo "Unresolved libraries in ${binary}:"; echo "$libs"; exit 1 ;; \
+    esac; \
+    done
 
 ################
 # 4 Entrypoint #
diff --git a/collabora/README.md b/collabora/README.md
index 51c96cf83f..c6f04f87eb 100644
--- a/collabora/README.md
+++ b/collabora/README.md
@@ -52,22 +52,63 @@ Webui can be found at `https://homeassistant:9980/browser/dist/admin/admin.html`
 
 | Option | Type | Default | Description |
 |--------|------|---------|-------------|
-| `aliasgroup1` | str | | Nextcloud external domain with escaped dots using two \ (e.g. `nextcloud_domain\\.com`) |
-| `domain1` | str | | Collabora external domain with escaped dots using two \ (e.g. `code_domain\\.com`) |
+| `aliasgroup1` | str | | External address of the **Nextcloud** server allowed to use this Collabora (e.g. `https://nextcloud_domain\.com:443`) |
+| `aliasgroup2` | str | | A second Nextcloud server, same format as `aliasgroup1` |
+| `aliasgroup3` | str | | A third Nextcloud server, same format as `aliasgroup1` |
+| `server_name` | str | | External hostname (and port) of **this Collabora** server, as the browser reaches it (e.g. `code_domain.com:9980`). Set it when Collabora sits behind a reverse proxy |
+| `ssl_termination` | bool | `false` | Set to `true` when `ssl` is `false` but the browser reaches Collabora over `https` through a reverse proxy |
 | `extra_params` | str | | Extra parameters passed to the Collabora start script |
 | `ssl` | bool | `false` | Enable SSL using certificates from /ssl |
 | `certfile` | str | `fullchain.pem` | Certificate file name located in /ssl |
 | `keyfile` | str | `privkey.pem` | Private key file name located in /ssl |
+| `cert_domain` | str | | Common name of the self-signed certificate generated when `ssl` is `false` |
 | `username` | str | | Username for the Collabora admin console |
 | `password` | str | | Password for the Collabora admin console |
 | `dictionaries` | str | | Space-separated list of dictionary languages to install |
+| `domain1` | str | | **Deprecated**, use `server_name` instead |
+
+#### About the escaped dots in `aliasgroup*`
+
+Collabora matches the `aliasgroup*` addresses as **regular expressions**, so a dot
+has to be escaped with a **single** backslash: `next\.duckdns\.org`, not
+`next\\.duckdns\\.org`. A doubled backslash means "a literal backslash followed by
+any character", which never matches a real hostname, and Collabora then rejects the
+Nextcloud server.
+
+Earlier versions of this page asked for two backslashes, which was wrong. The add-on
+now normalises whatever you type, so `next.duckdns.org`, `next\.duckdns\.org` and
+`next\\.duckdns\\.org` all end up as the same correct pattern. The value that is
+really handed to Collabora is printed in the add-on log at startup:
+
+```text
+Allowed Nextcloud host aliasgroup1: https://next\.duckdns\.org:443
+```
+
+Values containing other regex characters (`*`, `|`, `(`, `[`, …) are left untouched,
+so hand-written patterns keep working.
+
+`server_name` is **not** a regular expression: write it as a plain hostname, without
+backslashes.
 
 ### Example configuration
 
+Nextcloud on `https://next.duckdns.org` and Collabora reachable on
+`https://code.duckdns.org:9980`, with a reverse proxy handling the certificates:
+
 ```yaml
-aliasgroup1: nextcloud_domain\\.com
-domain1: code_domain\\.com
-extra_params: ""
+aliasgroup1: https://next\.duckdns\.org:443
+server_name: code.duckdns.org:9980
+ssl_termination: true
+ssl: false
+username: admin
+password: changeme
+```
+
+Same setup, but letting the add-on serve the certificates itself from `/ssl`:
+
+```yaml
+aliasgroup1: https://next\.duckdns\.org:443
+server_name: code.duckdns.org:9980
 ssl: true
 certfile: fullchain.pem
 keyfile: privkey.pem
@@ -81,7 +122,19 @@ password: changeme
 1. Start the add-on and expose the Collabora server to an external domain.
 1. Install and configure the Nextcloud add-on.
 1. Inside Nextcloud, install the **Nextcloud Office** app.
-1. In Nextcloud **Administration Settings → Office**, set the Collabora server URL to `https://yourdomain:9980` and enable **Disable certificate validation**.
+1. In Nextcloud **Administration Settings → Office**, set the Collabora server URL to
+   the **Collabora** address, not the Nextcloud one — with the example above that is
+   `https://code.duckdns.org:9980` — and enable **Disable certificate validation** if
+   the add-on serves a self-signed certificate.
+1. Add both hostnames to the Nextcloud `trusted_domains`.
+
+The two hostnames have different roles, and swapping them is the most common cause of
+`Could not establish connection to the Collabora Online server`:
+
+- `aliasgroup1` is the **Nextcloud** address, it tells Collabora which server is
+  allowed to ask it to open documents.
+- `server_name` is the **Collabora** address, it tells Collabora which URL to hand
+  back to the browser.
 
 ### Custom Scripts and Environment Variables
 
diff --git a/collabora/config.yaml b/collabora/config.yaml
index a152277ecb..22ac07fc4d 100644
--- a/collabora/config.yaml
+++ b/collabora/config.yaml
@@ -15,7 +15,7 @@ options:
   env_vars: []
   aliasgroup1: ""
   certfile: fullchain.pem
-  domain1: ""
+  server_name: ""
   extra_params:
     --o:ssl.enable=false --o:user_interface.use_integration_theme=false
     --o:net.proto=IPv4
@@ -33,7 +33,9 @@ schema:
       value: str?
   TZ: str?
   aliasgroup1: str
-  cert_domain: bool?
+  aliasgroup2: str?
+  aliasgroup3: str?
+  cert_domain: str?
   certfile: str
   dictionaries: str?
   domain1: str?
@@ -42,8 +44,9 @@ schema:
   password: password
   server_name: str?
   ssl: bool
+  ssl_termination: bool?
   username: str
 slug: collabora
 url: https://github.com/alexbelgium/hassio-addons
-version: "1.3.0"
+version: "26.04.2.4.1"
 webui: "[PROTO:ssl]://[HOST]:[PORT:9980]/browser/dist/admin/admin.html"
diff --git a/collabora/rootfs/etc/cont-init.d/99-run.sh b/collabora/rootfs/etc/cont-init.d/99-run.sh
index c09ba1f182..95b0d33240 100755
--- a/collabora/rootfs/etc/cont-init.d/99-run.sh
+++ b/collabora/rootfs/etc/cont-init.d/99-run.sh
@@ -2,9 +2,58 @@
 # shellcheck shell=bash
 set -e
 
-if bashio::config.has_value 'domain'; then
-    domain="$(bashio::config 'domain')"
-    export domain
+# coolwsd matches storage.wopi.alias_groups host/alias entries as regular
+# expressions, so every dot has to be escaped with a single backslash. The value
+# is typed by hand in the add-on options, where it is easy to end up with no
+# escaping at all or with doubled backslashes, and a wrong pattern silently
+# never matches: Collabora then refuses the Nextcloud host. Accept all three
+# spellings and always hand coolwsd the canonical single-escaped form.
+REGEX_METACHARACTERS='][(){}|*+?^$'
+normalise_wopi_host() {
+    local value="$1"
+
+    # A value containing regex metacharacters was written by someone who knows
+    # what they are doing, leave it exactly as-is.
+    if [[ "$value" == *["$REGEX_METACHARACTERS"]* ]]; then
+        printf '%s' "$value"
+        return
+    fi
+
+    value="${value//\\/}"   # drop whatever escaping was typed, at any depth
+    value="${value//./\\.}" # re-escape every dot exactly once
+    printf '%s' "$value"
+}
+
+# server_name is a literal "hostname[:port]", not a regex and not a URL
+normalise_server_name() {
+    local value="$1"
+    value="${value//\\/}"  # never escaped, drop backslashes if any were copied over
+    value="${value#*://}"  # strip the scheme
+    value="${value%%/*}"   # strip any path
+    printf '%s' "$value"
+}
+
+for index in 1 2 3; do
+    if bashio::config.has_value "aliasgroup${index}"; then
+        aliasgroup="$(normalise_wopi_host "$(bashio::config "aliasgroup${index}")")"
+        export "aliasgroup${index}=${aliasgroup}"
+        bashio::log.info "Allowed Nextcloud host aliasgroup${index}: ${aliasgroup}"
+    fi
+done
+
+if bashio::config.has_value 'server_name'; then
+    server_name="$(normalise_server_name "$(bashio::config 'server_name')")"
+    export server_name
+elif bashio::config.has_value 'domain1'; then
+    # domain1 predates server_name and was documented as "the Collabora external
+    # domain", which is what server_name means to coolwsd. It was never actually
+    # passed to Collabora, so honour it here rather than keep ignoring it.
+    server_name="$(normalise_server_name "$(bashio::config 'domain1')")"
+    export server_name
+    bashio::log.warning "domain1 is deprecated, please use server_name instead"
+fi
+if [ -n "${server_name:-}" ]; then
+    bashio::log.info "Collabora public hostname (server_name): ${server_name}"
 fi
 
 if bashio::config.has_value 'username'; then
@@ -17,9 +66,9 @@ if bashio::config.has_value 'password'; then
     export password
 fi
 
-if bashio::config.has_value 'aliasgroup1'; then
-    aliasgroup1="$(bashio::config 'aliasgroup1')"
-    export aliasgroup1
+if bashio::config.has_value 'cert_domain'; then
+    cert_domain="$(bashio::config 'cert_domain')"
+    export cert_domain
 fi
 
 if bashio::config.has_value 'dictionaries'; then
@@ -32,6 +81,12 @@ if bashio::config.has_value 'extra_params'; then
     extra_params="$(bashio::config 'extra_params')"
 fi
 
+# The add-on ssl option is authoritative. coolwsd defaults ssl.enable to true,
+# so merely clearing extra_params used to re-enable its self-signed HTTPS even
+# when ssl was false, which breaks reverse proxies expecting plain HTTP.
+extra_params="${extra_params//--o:ssl.enable=false/}"
+extra_params="${extra_params//--o:ssl.enable=true/}"
+
 if bashio::config.true 'ssl'; then
     export DONT_GEN_SSL_CERT=true
     bashio::config.require.ssl
@@ -45,16 +100,31 @@ if bashio::config.true 'ssl'; then
         bashio::log.error "Key file /ssl/${keyfile} not found"
         exit 1
     fi
-    cp -f /ssl/${keyfile} /etc/coolwsd/key.pem
-    cp -f /ssl/${certfile} /etc/coolwsd/cert.pem
-    cp -f /ssl/${certfile} /etc/coolwsd/ca-chain.cert.pem
-    extra_params="${extra_params/--o:ssl.enable=false/}"
+    # Point Collabora at the copies rather than at /ssl. coolwsd runs as uid
+    # 1001 and /ssl is mounted read-only with whatever ownership the certificate
+    # tooling left behind, which for a private key is commonly root-only. These
+    # copies are picked up by the chown below, so they are readable regardless.
+    cp -f "/ssl/${keyfile}" /etc/coolwsd/key.pem
+    cp -f "/ssl/${certfile}" /etc/coolwsd/cert.pem
+    cp -f "/ssl/${certfile}" /etc/coolwsd/ca-chain.cert.pem
+    chmod 600 /etc/coolwsd/key.pem
     extra_params="${extra_params} \
-         --o:ssl.enable=true 
+         --o:ssl.enable=true \
          --o:ssl.termination=false \
-         --o:ssl.cert_file_path=/ssl/${certfile} \
-         --o:ssl.key_file_path=/ssl/${keyfile} \
-         --o:ssl.ca_file_path=/ssl/${certfile}"
+         --o:ssl.cert_file_path=/etc/coolwsd/cert.pem \
+         --o:ssl.key_file_path=/etc/coolwsd/key.pem \
+         --o:ssl.ca_file_path=/etc/coolwsd/ca-chain.cert.pem"
+else
+    extra_params="${extra_params} --o:ssl.enable=false"
+    if [[ "$extra_params" != *ssl.termination* ]]; then
+        # With SSL disabled, termination must be enabled when a reverse proxy
+        # exposes Collabora over https, otherwise it advertises http/ws URLs.
+        if bashio::config.true 'ssl_termination'; then
+            extra_params="${extra_params} --o:ssl.termination=true"
+        elif ! bashio::config.has_value 'ssl_termination'; then
+            bashio::log.notice "If Collabora is reached over https through a reverse proxy, set ssl_termination to true"
+        fi
+    fi
 fi
 
 export extra_params
@@ -83,4 +153,9 @@ chown -R 1001 /etc/coolwsd
 chmod -R 755 /opt/cool/systemplate
 
 bashio::log.info "Starting Collabora Online..."
-su -p -s /bin/bash "$(getent passwd 1001 | cut -d: -f1)" -c "/start-collabora-online.sh"
+# coolwsd refuses to run as root. The official image used to ship
+# /start-collabora-online.sh, which is gone since it became distroless, so the
+# add-on provides its own launcher. It reads everything from the environment,
+# which su -p preserves.
+export HOME=/opt/cool
+su -p -s /bin/bash cool -c /usr/local/bin/collabora-run.sh
diff --git a/collabora/rootfs/usr/local/bin/collabora-run.sh b/collabora/rootfs/usr/local/bin/collabora-run.sh
new file mode 100644
index 0000000000..a3264ebe11
--- /dev/null
+++ b/collabora/rootfs/usr/local/bin/collabora-run.sh
@@ -0,0 +1,55 @@
+#!/bin/bash
+# shellcheck shell=bash
+#
+# Launch coolwsd.
+#
+# The official image used to ship /start-collabora-online.sh and set it as its
+# entrypoint. Since the move to a distroless image that script is gone, so the
+# add-on provides its own equivalent. It is invoked as uid 1001 by
+# /etc/cont-init.d/99-run.sh and takes everything from the environment, which
+# avoids re-quoting extra_params through su.
+set -e
+
+# Collabora serves https itself unless the add-on already installed real
+# certificates, in which case 99-run.sh exports DONT_GEN_SSL_CERT.
+cert_params=""
+if [ -z "${DONT_GEN_SSL_CERT:-}" ]; then
+    SSL_DIR="/tmp/ssl"
+    mkdir -p "${SSL_DIR}/certs/ca" "${SSL_DIR}/certs/servers/localhost" "${SSL_DIR}/certs/tmp"
+
+    openssl genrsa -out "${SSL_DIR}/certs/ca/root.key.pem" 2048
+    openssl req -x509 -new -nodes \
+        -key "${SSL_DIR}/certs/ca/root.key.pem" -days 9131 \
+        -out "${SSL_DIR}/certs/ca/root.crt.pem" \
+        -subj "/C=DE/ST=BW/L=Stuttgart/O=Dummy Authority/CN=Dummy Authority"
+
+    openssl genrsa -out "${SSL_DIR}/certs/servers/localhost/privkey.pem" 2048
+    openssl req -new -sha256 \
+        -key "${SSL_DIR}/certs/servers/localhost/privkey.pem" \
+        -out "${SSL_DIR}/certs/tmp/localhost.csr.pem" \
+        -subj "/C=DE/ST=BW/L=Stuttgart/O=Dummy Authority/CN=${cert_domain:-localhost}"
+    openssl x509 -req -days 9131 \
+        -in "${SSL_DIR}/certs/tmp/localhost.csr.pem" \
+        -CA "${SSL_DIR}/certs/ca/root.crt.pem" \
+        -CAkey "${SSL_DIR}/certs/ca/root.key.pem" -CAcreateserial \
+        -out "${SSL_DIR}/certs/servers/localhost/cert.pem"
+
+    cert_params="--o:ssl.cert_file_path=${SSL_DIR}/certs/servers/localhost/cert.pem \
+        --o:ssl.key_file_path=${SSL_DIR}/certs/servers/localhost/privkey.pem \
+        --o:ssl.ca_file_path=${SSL_DIR}/certs/ca/root.crt.pem"
+fi
+
+# Flags mirror the entrypoint of the official image. extra_params is expanded
+# last so that add-on options and user overrides win.
+# shellcheck disable=SC2086
+exec /usr/bin/coolwsd \
+    --version \
+    --use-env-vars \
+    ${cert_params} \
+    --o:sys_template_path=/opt/cool/systemplate \
+    --o:child_root_path=/opt/cool/child-roots \
+    --o:file_server_root_path=/usr/share/coolwsd \
+    --o:cache_files.path=/opt/cool/cache \
+    --o:logging.color=false \
+    --o:stop_on_config_change=true \
+    ${extra_params:-}
diff --git a/collabora/updater.json b/collabora/updater.json
index 35f757568b..c8f8b13ede 100644
--- a/collabora/updater.json
+++ b/collabora/updater.json
@@ -1,8 +1,9 @@
 {
-  "last_update": "2026-07-16",
+  "github_exclude": "sha256",
+  "last_update": "2026-07-26",
   "repository": "alexbelgium/hassio-addons",
   "slug": "collabora",
-  "source": "github",
-  "upstream_repo": "CollaboraOnline/online",
-  "upstream_version": "1.3.0"
+  "source": "dockerhub",
+  "upstream_repo": "collabora/code",
+  "upstream_version": "26.04.2.4.1"
 }