diff --git a/internal/web/service/key_gen_parse_test.go b/internal/web/service/key_gen_parse_test.go
new file mode 100644
index 000000000..68aeb3f69
--- /dev/null
+++ b/internal/web/service/key_gen_parse_test.go
@@ -0,0 +1,37 @@
+package service
+
+import "testing"
+
+// The x25519 / mldsa65 / mlkem768 key generators parse xray's stdout by fixed
+// slice index. A short or reformatted output (a future xray release, or a
+// binary that failed silently) must yield an error, never an out-of-range
+// panic that 500s the handler.
+func TestParseXrayKeyPairOutput(t *testing.T) {
+	a, b, err := parseXrayKeyPairOutput("Private key: abc123\nPublic key: def456\n")
+	if err != nil {
+		t.Fatalf("well-formed output errored: %v", err)
+	}
+	if a != "abc123" || b != "def456" {
+		t.Fatalf("got (%q, %q), want (abc123, def456)", a, b)
+	}
+
+	malformed := []string{
+		"",
+		"only one line: value",
+		"Private key: abc\n",
+		"no colon here\nno colon two",
+		"Private key\nPublic key",
+	}
+	for _, out := range malformed {
+		func() {
+			defer func() {
+				if r := recover(); r != nil {
+					t.Errorf("parseXrayKeyPairOutput panicked on %q: %v", out, r)
+				}
+			}()
+			if _, _, err := parseXrayKeyPairOutput(out); err == nil {
+				t.Errorf("expected error for malformed output %q, got nil", out)
+			}
+		}()
+	}
+}
diff --git a/internal/web/service/server.go b/internal/web/service/server.go
index dd190d4b2..7afa144ca 100644
--- a/internal/web/service/server.go
+++ b/internal/web/service/server.go
@@ -2023,6 +2023,24 @@ func (s *ServerService) UpdateGeofile(fileName string) error {
 	return nil
 }
 
+// parseXrayKeyPairOutput reads the two-line "Label: value" output that xray's
+// key-generation subcommands (x25519, mldsa65, mlkem768) print and returns the
+// two values. Short or label-less output yields an error instead of panicking
+// on an out-of-range slice index, so a future xray version that changes the
+// format degrades to a 500 with a message rather than a crash.
+func parseXrayKeyPairOutput(output string) (string, string, error) {
+	lines := strings.Split(output, "\n")
+	if len(lines) < 2 {
+		return "", "", common.NewError("unexpected key generator output")
+	}
+	first := strings.Split(lines[0], ":")
+	second := strings.Split(lines[1], ":")
+	if len(first) < 2 || len(second) < 2 {
+		return "", "", common.NewError("unexpected key generator output")
+	}
+	return strings.TrimSpace(first[1]), strings.TrimSpace(second[1]), nil
+}
+
 func (s *ServerService) GetNewX25519Cert() (any, error) {
 	// Run the command
 	cmd := exec.CommandContext(context.Background(), xray.GetBinaryPath(), "x25519")
@@ -2033,13 +2051,10 @@ func (s *ServerService) GetNewX25519Cert() (any, error) {
 		return nil, err
 	}
 
-	lines := strings.Split(out.String(), "\n")
-
-	privateKeyLine := strings.Split(lines[0], ":")
-	publicKeyLine := strings.Split(lines[1], ":")
-
-	privateKey := strings.TrimSpace(privateKeyLine[1])
-	publicKey := strings.TrimSpace(publicKeyLine[1])
+	privateKey, publicKey, err := parseXrayKeyPairOutput(out.String())
+	if err != nil {
+		return nil, err
+	}
 
 	keyPair := map[string]any{
 		"privateKey": privateKey,
@@ -2059,13 +2074,10 @@ func (s *ServerService) GetNewmldsa65() (any, error) {
 		return nil, err
 	}
 
-	lines := strings.Split(out.String(), "\n")
-
-	SeedLine := strings.Split(lines[0], ":")
-	VerifyLine := strings.Split(lines[1], ":")
-
-	seed := strings.TrimSpace(SeedLine[1])
-	verify := strings.TrimSpace(VerifyLine[1])
+	seed, verify, err := parseXrayKeyPairOutput(out.String())
+	if err != nil {
+		return nil, err
+	}
 
 	keyPair := map[string]any{
 		"seed":   seed,
@@ -2381,13 +2393,10 @@ func (s *ServerService) GetNewmlkem768() (any, error) {
 		return nil, err
 	}
 
-	lines := strings.Split(out.String(), "\n")
-
-	SeedLine := strings.Split(lines[0], ":")
-	ClientLine := strings.Split(lines[1], ":")
-
-	seed := strings.TrimSpace(SeedLine[1])
-	client := strings.TrimSpace(ClientLine[1])
+	seed, client, err := parseXrayKeyPairOutput(out.String())
+	if err != nil {
+		return nil, err
+	}
 
 	keyPair := map[string]any{
 		"seed":   seed,