diff --git a/apps/client/src/common/api/project.ts b/apps/client/src/common/api/project.ts
index 1fd1cf52f..c31a2f72a 100644
--- a/apps/client/src/common/api/project.ts
+++ b/apps/client/src/common/api/project.ts
@@ -21,8 +21,9 @@ export async function getProjectData(options?: RequestOptions): Promise<ProjectD
 /**
  * HTTP request to mutate project data
  */
-export async function postProjectData(data: ProjectData): Promise<AxiosResponse<ProjectData>> {
-  return axios.post(projectPath, data);
+export async function postProjectData(data: ProjectData): Promise<ProjectData> {
+  const response = await axios.post(projectPath, data);
+  return response.data;
 }
 
 /**
diff --git a/apps/server/src/api-data/project-data/__tests__/projectData.parser.test.ts b/apps/server/src/api-data/project-data/__tests__/projectData.parser.test.ts
index 6fe4c1242..d6789a613 100644
--- a/apps/server/src/api-data/project-data/__tests__/projectData.parser.test.ts
+++ b/apps/server/src/api-data/project-data/__tests__/projectData.parser.test.ts
@@ -7,4 +7,25 @@ describe('parseProjectData()', () => {
     expect(result).toBeTypeOf('object');
     expect(errorEmitter).toHaveBeenCalledOnce();
   });
+
+  it('sanitises malformed custom project data', () => {
+    const errorEmitter = vi.fn();
+    const result = parseProjectData(
+      {
+        project: {
+          title: 'Demo',
+          description: '',
+          url: '',
+          info: '',
+          logo: null,
+          // @ts-expect-error -- checking malformed data
+          custom: '{"networkInterfaces":[{"name":"localhost","address":"127.0.0.1"}]}',
+        },
+      },
+      errorEmitter,
+    );
+
+    expect(result.custom).toEqual([]);
+    expect(errorEmitter).toHaveBeenCalledWith('Project custom data is invalid, using defaults');
+  });
 });
diff --git a/apps/server/src/api-data/project-data/projectData.parser.ts b/apps/server/src/api-data/project-data/projectData.parser.ts
index 73ff787cd..9380f767d 100644
--- a/apps/server/src/api-data/project-data/projectData.parser.ts
+++ b/apps/server/src/api-data/project-data/projectData.parser.ts
@@ -22,6 +22,53 @@ export function parseProjectData(data: Partial<DatabaseModel>, emitError?: Error
     url: data.project.url ?? defaultProject.url,
     info: data.project.info ?? defaultProject.info,
     logo: data.project.logo ?? defaultProject.logo,
-    custom: data.project.custom ?? defaultProject.custom,
+    custom: parseCustomProjectData(data.project.custom, defaultProject.custom, emitError),
   };
 }
+
+function isProjectCustomEntry(entry: unknown): entry is ProjectData['custom'][number] {
+  if (typeof entry !== 'object' || entry === null || Array.isArray(entry)) {
+    return false;
+  }
+
+  const { title, value, url } = entry as Record<string, unknown>;
+
+  return typeof title === 'string' && typeof value === 'string' && (url === undefined || typeof url === 'string');
+}
+
+function parseCustomProjectData(
+  data: unknown,
+  defaultCustomData: ProjectData['custom'],
+  emitError?: ErrorEmitter,
+): ProjectData['custom'] {
+  if (!Array.isArray(data)) {
+    if (data !== undefined) {
+      emitError?.('Project custom data is invalid, using defaults');
+    }
+    return defaultCustomData;
+  }
+
+  const parsed: ProjectData['custom'] = [];
+  let skippedInvalidEntry = false;
+
+  for (let i = 0; i < data.length; i++) {
+    const entry = data[i];
+
+    if (!isProjectCustomEntry(entry)) {
+      skippedInvalidEntry = true;
+      continue;
+    }
+
+    parsed.push({
+      title: entry.title,
+      value: entry.value,
+      url: entry.url ?? '',
+    });
+  }
+
+  if (skippedInvalidEntry) {
+    emitError?.('Project custom data contained invalid entries, skipping them');
+  }
+
+  return parsed;
+}