diff --git a/backend/src/ee/services/permission/permission-service.ts b/backend/src/ee/services/permission/permission-service.ts
index d05ce34e2..d632be3df 100644
--- a/backend/src/ee/services/permission/permission-service.ts
+++ b/backend/src/ee/services/permission/permission-service.ts
@@ -13,6 +13,7 @@ import { conditionsMatcher } from "@app/lib/casl";
 import { BadRequestError, UnauthorizedError } from "@app/lib/errors";
 import { ActorAuthMethod, ActorType } from "@app/services/auth/auth-type";
 import { TOrgRoleDALFactory } from "@app/services/org/org-role-dal";
+import { TProjectDALFactory } from "@app/services/project/project-dal";
 import { TProjectRoleDALFactory } from "@app/services/project-role/project-role-dal";
 import { TServiceTokenDALFactory } from "@app/services/service-token/service-token-dal";
 
@@ -33,6 +34,7 @@ type TPermissionServiceFactoryDep = {
   orgRoleDAL: Pick<TOrgRoleDALFactory, "findOne">;
   projectRoleDAL: Pick<TProjectRoleDALFactory, "findOne">;
   serviceTokenDAL: Pick<TServiceTokenDALFactory, "findById">;
+  projectDAL: Pick<TProjectDALFactory, "findById">;
   permissionDAL: TPermissionDALFactory;
 };
 
@@ -42,7 +44,8 @@ export const permissionServiceFactory = ({
   permissionDAL,
   orgRoleDAL,
   projectRoleDAL,
-  serviceTokenDAL
+  serviceTokenDAL,
+  projectDAL
 }: TPermissionServiceFactoryDep) => {
   const buildOrgPermission = (role: string, permission?: unknown) => {
     switch (role) {
@@ -99,7 +102,7 @@ export const permissionServiceFactory = ({
 
   /*
    * Get user permission in an organization
-   * */
+   */
   const getUserOrgPermission = async (
     userId: string,
     orgId: string,
@@ -112,8 +115,13 @@ export const permissionServiceFactory = ({
       throw new BadRequestError({ name: "Custom permission not found" });
     }
 
-    if (membership.orgId !== userOrgId) {
-      throw new UnauthorizedError({ name: "You are not a member of this organization" });
+    // If the org ID is API_KEY, the request is being made with an API Key.
+    // Since we can't scope API keys to an organization, we'll need to do an arbitrary check to see if the user is a member of the organization.
+
+    // Extra: This means that when users are using API keys to make requests, they can't use slug-based routes.
+    // Slug-based routes depend on the organization ID being present on the request, since project slugs aren't globally unique, and we need a way to filter by organization.
+    if (userOrgId !== "API_KEY" && membership.orgId !== userOrgId) {
+      throw new UnauthorizedError({ name: "You are not logged into this organization" });
     }
 
     validateOrgSAML(authMethod, membership.orgAuthEnforced);
@@ -179,8 +187,13 @@ export const permissionServiceFactory = ({
       throw new BadRequestError({ name: "Custom permission not found" });
     }
 
-    if (membership.orgId !== userOrgId) {
-      throw new UnauthorizedError({ name: "You are not a member of this organization" });
+    // If the org ID is API_KEY, the request is being made with an API Key.
+    // Since we can't scope API keys to an organization, we'll need to do an arbitrary check to see if the user is a member of the organization.
+
+    // Extra: This means that when users are using API keys to make requests, they can't use slug-based routes.
+    // Slug-based routes depend on the organization ID being present on the request, since project slugs aren't globally unique, and we need a way to filter by organization.
+    if (userOrgId !== "API_KEY" && membership.orgId !== userOrgId) {
+      throw new UnauthorizedError({ name: "You are not logged into this organization" });
     }
 
     validateOrgSAML(authMethod, membership.orgAuthEnforced);
@@ -195,7 +208,8 @@ export const permissionServiceFactory = ({
 
   const getIdentityProjectPermission = async (
     identityId: string,
-    projectId: string
+    projectId: string,
+    identityOrgId: string | undefined
   ): Promise<TProjectPermissionRT<ActorType.IDENTITY>> => {
     const identityProjectPermission = await permissionDAL.getProjectIdentityPermission(identityId, projectId);
     if (!identityProjectPermission) throw new UnauthorizedError({ name: "Identity not in project" });
@@ -208,6 +222,10 @@ export const permissionServiceFactory = ({
       throw new BadRequestError({ name: "Custom permission not found" });
     }
 
+    if (identityProjectPermission.orgId !== identityOrgId) {
+      throw new UnauthorizedError({ name: "You are not a member of this organization" });
+    }
+
     return {
       permission: buildProjectPermission(identityProjectPermission.roles),
       membership: identityProjectPermission,
@@ -218,14 +236,32 @@ export const permissionServiceFactory = ({
     };
   };
 
-  const getServiceTokenProjectPermission = async (serviceTokenId: string, projectId: string) => {
+  const getServiceTokenProjectPermission = async (
+    serviceTokenId: string,
+    projectId: string,
+    actorOrgId: string | undefined
+  ) => {
     const serviceToken = await serviceTokenDAL.findById(serviceTokenId);
     if (!serviceToken) throw new BadRequestError({ message: "Service token not found" });
 
+    const serviceTokenProject = await projectDAL.findById(serviceToken.projectId);
+
+    if (!serviceTokenProject) throw new BadRequestError({ message: "Service token not linked to a project" });
+
+    if (serviceTokenProject.orgId !== actorOrgId) {
+      throw new UnauthorizedError({ message: "Service token not a part of this organization" });
+    }
+
     if (serviceToken.projectId !== projectId)
       throw new UnauthorizedError({
         message: "Failed to find service authorization for given project"
       });
+
+    if (serviceTokenProject.orgId !== actorOrgId)
+      throw new UnauthorizedError({
+        message: "Failed to find service authorization for given project"
+      });
+
     const scopes = ServiceTokenScopes.parse(serviceToken.scopes || []);
     return {
       permission: buildServiceTokenProjectPermission(scopes, serviceToken.permissions),
@@ -260,9 +296,9 @@ export const permissionServiceFactory = ({
       case ActorType.USER:
         return getUserProjectPermission(id, projectId, actorAuthMethod, actorOrgId) as Promise<TProjectPermissionRT<T>>;
       case ActorType.SERVICE:
-        return getServiceTokenProjectPermission(id, projectId) as Promise<TProjectPermissionRT<T>>;
+        return getServiceTokenProjectPermission(id, projectId, actorOrgId) as Promise<TProjectPermissionRT<T>>;
       case ActorType.IDENTITY:
-        return getIdentityProjectPermission(id, projectId) as Promise<TProjectPermissionRT<T>>;
+        return getIdentityProjectPermission(id, projectId, actorOrgId) as Promise<TProjectPermissionRT<T>>;
       default:
         throw new UnauthorizedError({
           message: "Permission not defined",