diff --git a/.github/ISSUE_TEMPLATE/release_checklist.md b/.github/ISSUE_TEMPLATE/release_checklist.md
index df97d6fff3..acca08b093 100644
--- a/.github/ISSUE_TEMPLATE/release_checklist.md
+++ b/.github/ISSUE_TEMPLATE/release_checklist.md
@@ -17,6 +17,13 @@ Refer to the [Deployment](https://data-safe-haven.readthedocs.io/en/latest/deplo
 - [ ] Consult the `data-safe-haven/VERSIONING.md` guide and determine the version number of the new release. Record it in the title of this issue.
 - [ ] Create a release branch called e.g. `release-v0.0.1`
 - [ ] Draft a changelog for the release similar to our previous releases, see https://github.com/alan-turing-institute/data-safe-haven/releases
+
+### For patch releases only
+
+- [ ] Confirm that the resource to which the patch applies can be successfully deployed
+
+### For minor releases and above
+
 - [ ] Deploy an SHM from this branch and save a transcript of the deployment logs
 - [ ] Build an SRE compute image (SRD) and save transcripts of the logs
 - Using the new image, deploy a tier 2 and a tier 3 SRE
@@ -24,7 +31,7 @@ Refer to the [Deployment](https://data-safe-haven.readthedocs.io/en/latest/deplo
     - [ ] Save the transcript of your tier 3 SRE deployment
 - [ ] Complete the [Security evaluation checklist](https://data-safe-haven.readthedocs.io/en/latest/deployment/security_checklist.html) from the deployment documentation
 
-### For major releases
+### For major releases only
 
 - [ ] Confirm that a third party has carried out a full penetration test evaluating:
   1. external attack surface
diff --git a/SECURITY.md b/SECURITY.md
index f11adf3995..4fb522a9b1 100644
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -7,8 +7,8 @@ All organisations using an earlier version in production should update to the la
 
 | Version                                                                                 | Supported          |
 | --------------------------------------------------------------------------------------- | ------------------ |
-| [4.2.0](https://github.com/alan-turing-institute/data-safe-haven/releases/tag/v4.2.0)   | :white_check_mark: |
-| < 4.2.0                                                                                 | :x:                |
+| [4.2.1](https://github.com/alan-turing-institute/data-safe-haven/releases/tag/v4.2.1)   | :white_check_mark: |
+| < 4.2.1                                                                                 | :x:                |
 
 ## Reporting a Vulnerability
 
diff --git a/VERSIONING.md b/VERSIONING.md
index 6004e1b1e4..41801b06b5 100644
--- a/VERSIONING.md
+++ b/VERSIONING.md
@@ -67,6 +67,7 @@ We usually deploy the latest available version of the Data Safe Haven for each o
 | May 2023         | DSG 2023-05                   | [v4.0.3](https://github.com/alan-turing-institute/data-safe-haven/releases/tag/v4.0.3)           |
 | September 2023   | DDRC DSG Exeter 2023          | [v4.1.0](https://github.com/alan-turing-institute/data-safe-haven/releases/tag/v4.1.0)           |
 | December 2023    | DSG 2023-12                   | [v4.1.0](https://github.com/alan-turing-institute/data-safe-haven/releases/tag/v4.1.0)           |
+| May 2024         | DSG 2024-05                   | [v4.2.1](https://github.com/alan-turing-institute/data-safe-haven/releases/tag/v4.2.1)           |
 
 Additionally, a production instance of DSH is maintained for use by research projects at the Turing.
 
diff --git a/deployment/secure_research_environment/cloud_init/resources/guacamole_docker_compose.mustache.yaml b/deployment/secure_research_environment/cloud_init/resources/guacamole_docker_compose.mustache.yaml
index d3493ae0bd..af716fd6f0 100644
--- a/deployment/secure_research_environment/cloud_init/resources/guacamole_docker_compose.mustache.yaml
+++ b/deployment/secure_research_environment/cloud_init/resources/guacamole_docker_compose.mustache.yaml
@@ -35,7 +35,7 @@ services:
 
     guacd:
         container_name: guacd_guacamole_compose
-        image: guacamole/guacd:1.5.4
+        image: guacamole/guacd:1.5.5
         networks:
             - network_private
         volumes:
@@ -47,7 +47,7 @@ services:
 
     guacamole:
         container_name: guacamole_guacamole_compose
-        image: guacamole/guacamole:1.5.4
+        image: guacamole/guacamole:1.5.5
         depends_on:
             guacd:
                 condition: service_started