diff --git a/backend/internal/kvm/kvm_test.go b/backend/internal/kvm/kvm_test.go
index fdfa5ec..76bf438 100644
--- a/backend/internal/kvm/kvm_test.go
+++ b/backend/internal/kvm/kvm_test.go
@@ -3,6 +3,7 @@ package kvm
 import (
 	"crypto/ed25519"
 	"crypto/rand"
+	"path/filepath"
 	"reflect"
 	"testing"
 
@@ -11,14 +12,15 @@ import (
 	"golang.org/x/crypto/ssh"
 )
 
-func TestLocalImageIDRejectsPathExpressions(t *testing.T) {
-	for _, id := range []string{"", ".", "..", "../../etc/passwd", `..\\..\\windows`, "/absolute"} {
-		if got := localImageID(id); got != "__invalid_image_id__" {
-			t.Fatalf("localImageID(%q) = %q", id, got)
+func TestImagePathUsesAllowlistedImageID(t *testing.T) {
+	for _, id := range []string{"", ".", "..", "../../etc/passwd", `..\\..\\windows`, "/absolute", "unknown-image"} {
+		if got := filepath.Base(ImagePath(id)); got != "__invalid_image_id__.qcow2" {
+			t.Fatalf("ImagePath(%q) basename = %q", id, got)
 		}
 	}
-	if got := localImageID("debian-13-kvm"); got != "debian-13-kvm" {
-		t.Fatalf("localImageID(valid) = %q", got)
+	validID := GetImages()[0].ID
+	if got := filepath.Base(ImagePath(validID)); got != validID+".qcow2" {
+		t.Fatalf("ImagePath(%q) basename = %q", validID, got)
 	}
 }
 
diff --git a/backend/internal/kvm/templates.go b/backend/internal/kvm/templates.go
index d36777d..5ca1e9e 100644
--- a/backend/internal/kvm/templates.go
+++ b/backend/internal/kvm/templates.go
@@ -4,7 +4,6 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
-	"strings"
 
 	"clicd/internal/config"
 )
@@ -193,10 +192,14 @@ func CacheDir() string {
 func ImagePath(id string) string {
 	img := FindImage(id)
 	ext := ".qcow2"
+	safeID := "__invalid_image_id__"
+	if img != nil {
+		safeID = img.ID
+	}
 	if img != nil && img.Distro == "windows" {
 		ext = ".iso"
 	}
-	fileName := localImageID(id) + ext
+	fileName := safeID + ext
 	for _, pool := range config.StoragePoolsForContent(config.StorageContentImages) {
 		candidate := filepath.Join(pool.Path, "images", "kvm", fileName)
 		if info, err := os.Stat(candidate); err == nil && !info.IsDir() {
@@ -210,15 +213,6 @@ func ImagePath(id string) string {
 	return filepath.Join(CacheDir(), fileName)
 }
 
-func localImageID(id string) string {
-	trimmed := strings.TrimSpace(id)
-	local := filepath.Base(trimmed)
-	if trimmed == "" || local == "." || local == ".." || local != trimmed || strings.ContainsAny(trimmed, `/\\`) {
-		return "__invalid_image_id__"
-	}
-	return local
-}
-
 // IsWindowsImage returns true if the image distro is "windows".
 func IsWindowsImage(id string) bool {
 	img := FindImage(id)
diff --git a/backend/internal/lxc/lxc.go b/backend/internal/lxc/lxc.go
index 12c7255..01efbe4 100644
--- a/backend/internal/lxc/lxc.go
+++ b/backend/internal/lxc/lxc.go
@@ -708,7 +708,7 @@ func (m *Manager) applyLANIPv4Config(lxcName string, cfg ContainerConfig) (strin
 		values["lxc.net.0.ipv4.gateway"] = strings.TrimSpace(cfg.LANIPv4Gateway)
 	}
 	seen := map[string]bool{}
-	next := make([]string, 0, len(lines)+len(values))
+	next := make([]string, 0, len(lines))
 	for _, line := range lines {
 		trimmed := strings.TrimSpace(line)
 		if !cfg.WantsLANStaticIPv4() && (strings.HasPrefix(trimmed, "lxc.net.0.ipv4.address") || strings.HasPrefix(trimmed, "lxc.net.0.ipv4.gateway")) {