diff --git a/docs/create-new-web-service-vm.md b/docs/guides/create-new-web-service-vm.md
similarity index 100%
rename from docs/create-new-web-service-vm.md
rename to docs/guides/create-new-web-service-vm.md
diff --git a/docs/setting_up_secrets_using_sops_for_a_new_host.md b/docs/guides/setting_up_secrets_using_sops_for_a_new_host.md
similarity index 100%
rename from docs/setting_up_secrets_using_sops_for_a_new_host.md
rename to docs/guides/setting_up_secrets_using_sops_for_a_new_host.md
diff --git a/docs/index.md b/docs/index.md
index e390c5e..9c1e48e 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -1,3 +1,5 @@
 # CCCHH Infrastructure Documentation
 
 Home for CCCHH infrastructure documentation.
+
+- **Guides**: Documentation on how to achieve various things.
diff --git a/inventories/chaosknoten/host_vars/cloud.yaml b/inventories/chaosknoten/host_vars/cloud.yaml
index 9c28d58..765a86b 100644
--- a/inventories/chaosknoten/host_vars/cloud.yaml
+++ b/inventories/chaosknoten/host_vars/cloud.yaml
@@ -1,7 +1,7 @@
 # renovate: datasource=docker depName=git.hamburg.ccc.de/ccchh/oci-images/nextcloud
 nextcloud__version: 32
 # renovate: datasource=docker depName=docker.io/library/postgres
-nextcloud__postgres_version: 15.17
+nextcloud__postgres_version: 18.4
 nextcloud__fqdn: cloud.hamburg.ccc.de
 nextcloud__data_dir: /data/nextcloud
 nextcloud__extra_configuration: "{{ lookup('ansible.builtin.template', 'resources/chaosknoten/cloud/nextcloud/extra_configuration.config.php.j2') }}"
diff --git a/resources/chaosknoten/lists/docker_compose/compose.yaml.j2 b/resources/chaosknoten/lists/docker_compose/compose.yaml.j2
index db605b5..58d1ed5 100644
--- a/resources/chaosknoten/lists/docker_compose/compose.yaml.j2
+++ b/resources/chaosknoten/lists/docker_compose/compose.yaml.j2
@@ -62,7 +62,7 @@ services:
       - POSTGRES_DB=mailmandb
       - POSTGRES_USER=mailman
       - "POSTGRES_PASSWORD={{ secret__lists__postgres_password }}"
-    image: docker.io/library/postgres:12-alpine
+    image: docker.io/library/postgres:18-alpine
     volumes:
       - /opt/mailman/database:/var/lib/postgresql/data
     networks:
diff --git a/resources/chaosknoten/pretalx/docker_compose/compose.yaml.j2 b/resources/chaosknoten/pretalx/docker_compose/compose.yaml.j2
index 0bbfcb8..091bd44 100644
--- a/resources/chaosknoten/pretalx/docker_compose/compose.yaml.j2
+++ b/resources/chaosknoten/pretalx/docker_compose/compose.yaml.j2
@@ -3,7 +3,7 @@
 
 services:
   database:
-    image: docker.io/library/postgres:15-alpine
+    image: docker.io/library/postgres:18-alpine
     environment:
       - "POSTGRES_USER=pretalx"
       - "POSTGRES_PASSWORD={{ secret__pretalx_db_password }}"