diff --git a/README.md b/README.md
index 6aff7e6..2ace871 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,9 @@ This project focuses on providing a high-performance, secure, and extensible Git
 - [x] **Programmable**: Extensible logic using JavaScript (Goja).
 - [x] **Reverse Proxy**: Support for proxying requests to backends.
 
+> [!WARNING]
+> **Security Note**: This project is designed for self-hosted/private environments. It does not perform domain ownership verification for CNAME aliases. In a multi-user environment, users could potentially "hijack" domains by claiming them in their `.pages.yaml`.
+
 
 ## Get Started
 
diff --git a/README_zh.md b/README_zh.md
index dbe2de8..1dd4201 100644
--- a/README_zh.md
+++ b/README_zh.md
@@ -18,6 +18,9 @@
 - [x] **可编程**: 使用 JavaScript (Goja) 编写自定义路由逻辑。
 - [x] **反向代理**: 支持将请求代理到后端服务。
 
+> [!WARNING]
+> **安全提示**: 本项目设计用于自托管或私有环境。它不对 CNAME 别名进行域名所有权验证。在多用户环境中，用户可能会通过在 `.pages.yaml` 中声明他人域名来实施“劫持”。
+
 
 ## Get Started
 
diff --git a/go.mod b/go.mod
index 65c2dfa..9d5a770 100644
--- a/go.mod
+++ b/go.mod
@@ -15,7 +15,7 @@ require (
 	github.com/pkg/errors v0.9.1
 	github.com/stretchr/testify v1.11.1
 	go.uber.org/zap v1.27.1
-	gopkg.d7z.net/middleware v0.0.0-20260131134426-cea18952b028
+	gopkg.d7z.net/middleware v0.0.0-20260131162733-c737c5341584
 	gopkg.in/yaml.v3 v3.0.1
 )
 
diff --git a/go.sum b/go.sum
index 3be44e7..284d989 100644
--- a/go.sum
+++ b/go.sum
@@ -168,6 +168,8 @@ gopkg.d7z.net/middleware v0.0.0-20260131122058-3c200930af2d h1:nNXZgc02tab2+WuAn
 gopkg.d7z.net/middleware v0.0.0-20260131122058-3c200930af2d/go.mod h1:TDqvtfgaXzOvm9gbG8t5FF0AKSKve8pcE9uBVix+1pU=
 gopkg.d7z.net/middleware v0.0.0-20260131134426-cea18952b028 h1:BPm7q2ys8IPHAQe01HBSkYH+2itXuP6DvVPZlg45tM4=
 gopkg.d7z.net/middleware v0.0.0-20260131134426-cea18952b028/go.mod h1:TDqvtfgaXzOvm9gbG8t5FF0AKSKve8pcE9uBVix+1pU=
+gopkg.d7z.net/middleware v0.0.0-20260131162733-c737c5341584 h1:Bdtk/GJQELmfVeoAEyCAUUzR90ZOx6qGA/M3Yjf09Ao=
+gopkg.d7z.net/middleware v0.0.0-20260131162733-c737c5341584/go.mod h1:TDqvtfgaXzOvm9gbG8t5FF0AKSKve8pcE9uBVix+1pU=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
diff --git a/pkg/core/alias.go b/pkg/core/alias.go
index 17fcce3..5b7f117 100644
--- a/pkg/core/alias.go
+++ b/pkg/core/alias.go
@@ -35,16 +35,50 @@ func (a *DomainAlias) Query(ctx context.Context, domain string) (*Alias, error)
 }
 
 func (a *DomainAlias) Bind(ctx context.Context, domains []string, owner, repo string) error {
-	oldDomains := make([]string, 0)
 	rKey := base64.URLEncoding.EncodeToString([]byte(fmt.Sprintf("%s/%s", owner, repo)))
-	if oldStr, err := a.config.Get(ctx, rKey); err == nil {
-		_ = json.Unmarshal([]byte(oldStr), &oldDomains)
-	}
-	for _, oldDomain := range oldDomains {
-		if err := a.Unbind(ctx, oldDomain); err != nil {
+
+	var oldDomains []string
+	domainsRaw, _ := json.Marshal(domains)
+
+	for {
+		success, err := a.config.PutIfNotExists(ctx, rKey, string(domainsRaw), kv.TTLKeep)
+		if err != nil {
 			return err
 		}
+		if success {
+			oldDomains = []string{}
+			break
+		}
+
+		oldStr, err := a.config.Get(ctx, rKey)
+		if err != nil {
+			continue
+		}
+
+		if err = json.Unmarshal([]byte(oldStr), &oldDomains); err != nil {
+			oldDomains = []string{}
+		}
+
+		success, err = a.config.CompareAndSwap(ctx, rKey, oldStr, string(domainsRaw))
+		if err != nil {
+			return err
+		}
+		if success {
+			break
+		}
 	}
+
+	newDomainsMap := make(map[string]bool)
+	for _, d := range domains {
+		newDomainsMap[d] = true
+	}
+
+	for _, oldDomain := range oldDomains {
+		if !newDomainsMap[oldDomain] {
+			_ = a.Unbind(ctx, oldDomain)
+		}
+	}
+
 	if len(domains) == 0 {
 		return nil
 	}
@@ -53,12 +87,8 @@ func (a *DomainAlias) Bind(ctx context.Context, domains []string, owner, repo st
 		Repo:  repo,
 	}
 	aliasMetaRaw, _ := json.Marshal(aliasMeta)
-	domainsRaw, _ := json.Marshal(domains)
-	_ = a.config.Put(ctx, rKey, string(domainsRaw), kv.TTLKeep)
 	for _, domain := range domains {
-		if err := a.config.Put(ctx, domain, string(aliasMetaRaw), kv.TTLKeep); err != nil {
-			return err
-		}
+		_ = a.config.Put(ctx, domain, string(aliasMetaRaw), kv.TTLKeep)
 	}
 	return nil
 }
diff --git a/pkg/core/meta.go b/pkg/core/meta.go
index 9513c99..3504bc3 100644
--- a/pkg/core/meta.go
+++ b/pkg/core/meta.go
@@ -201,7 +201,7 @@ func (s *ServerMeta) parsePageConfig(ctx context.Context, meta *PageMetaContent,
 	cname, err := vfs.ReadString(ctx, "CNAME")
 	if cname != "" && err == nil {
 		cname = strings.TrimSpace(cname)
-		if al, ok := s.aliasCheck(cname); ok {
+		if al, ok := s.AliasCheck(cname); ok {
 			alias = append(alias, al)
 		} else {
 			return fmt.Errorf("invalid alias %s", cname)
@@ -233,7 +233,7 @@ func (s *ServerMeta) parsePageConfig(ctx context.Context, meta *PageMetaContent,
 		if item == "" {
 			continue
 		}
-		if al, ok := s.aliasCheck(item); ok {
+		if al, ok := s.AliasCheck(item); ok {
 			alias = append(alias, al)
 		} else {
 			return fmt.Errorf("invalid alias %s", item)
@@ -269,9 +269,9 @@ func (s *ServerMeta) parsePageConfig(ctx context.Context, meta *PageMetaContent,
 	return nil
 }
 
-var regexpHostname = regexp.MustCompile(`^(?:([a-z0-9-]+|\*)\.)?([a-z0-9-]{1,61})\.([a-z0-9]{2,7})$`)
+var regexpHostname = regexp.MustCompile(`^([a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?\.)+[a-z]{2,18}$`)
 
-func (s *ServerMeta) aliasCheck(cname string) (string, bool) {
+func (s *ServerMeta) AliasCheck(cname string) (string, bool) {
 	cname = strings.TrimSpace(cname)
 	if !regexpHostname.MatchString(cname) {
 		return "", false
diff --git a/tests/cname_test.go b/tests/cname_test.go
new file mode 100644
index 0000000..86e3024
--- /dev/null
+++ b/tests/cname_test.go
@@ -0,0 +1,69 @@
+package tests
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"gopkg.d7z.net/gitea-pages/pkg/core"
+	"gopkg.d7z.net/middleware/kv"
+)
+
+func TestCNAMERegex(t *testing.T) {
+	db, _ := kv.NewMemory("")
+	meta := core.NewServerMeta(nil, nil, "example.com", nil, db, 0, 0, 0)
+
+	tests := []struct {
+		domain string
+		valid  bool
+	}{
+		{"a.com", true},
+		{"sub.a.com", true},
+		{"a.b.c.d.com", true},
+		{"invalid_name.com", false},
+		{"-start.com", false},
+		{"end-.com", false},
+		{"a.com-too-long-tld-xxxxxxxxxxxxxxxxxxx", false},
+	}
+
+	for _, tt := range tests {
+		_, ok := meta.AliasCheck(tt.domain)
+		assert.Equal(t, tt.valid, ok, "Testing domain: %s", tt.domain)
+	}
+}
+
+func TestAliasBindCAS(t *testing.T) {
+	db, _ := kv.NewMemory("")
+
+	alias := core.NewDomainAlias(db)
+
+	ctx := context.Background()
+
+	err := alias.Bind(ctx, []string{"a.com", "b.com"}, "owner1", "repo1")
+
+	assert.NoError(t, err)
+
+	a, err := alias.Query(ctx, "a.com")
+
+	assert.NoError(t, err)
+
+	if assert.NotNil(t, a) {
+		assert.Equal(t, "owner1", a.Owner)
+	}
+
+	err = alias.Bind(ctx, []string{"b.com", "c.com"}, "owner1", "repo1")
+
+	assert.NoError(t, err)
+
+	_, err = alias.Query(ctx, "a.com")
+
+	assert.Error(t, err)
+
+	a, err = alias.Query(ctx, "c.com")
+
+	assert.NoError(t, err)
+
+	if assert.NotNil(t, a) {
+		assert.Equal(t, "owner1", a.Owner)
+	}
+}