diff --git a/custom/conf/app.ini.sample b/custom/conf/app.ini.sample
index f823f68e4f268..774a1df59887b 100644
--- a/custom/conf/app.ini.sample
+++ b/custom/conf/app.ini.sample
@@ -402,6 +402,10 @@ SESSION_LIFE_TIME = 86400
 
 [picture]
 AVATAR_UPLOAD_PATH = data/avatars
+; Max Width and Height of uploaded avatars. This is to limit the amount of RAM
+; used when resizing the image.
+AVATAR_MAX_WIDTH = 4096
+AVATAR_MAX_HEIGHT = 3072
 ; Chinese users can choose "duoshuo"
 ; or a custom avatar source, like: http://cn.gravatar.com/avatar/
 GRAVATAR_SOURCE = gravatar
diff --git a/models/user.go b/models/user.go
index 653e994263222..5ac86587966a8 100644
--- a/models/user.go
+++ b/models/user.go
@@ -433,6 +433,17 @@ func (u *User) IsPasswordSet() bool {
 // UploadAvatar saves custom avatar for user.
 // FIXME: split uploads to different subdirs in case we have massive users.
 func (u *User) UploadAvatar(data []byte) error {
+	imgCfg, _, err := image.DecodeConfig(bytes.NewReader(data))
+	if err != nil {
+		return fmt.Errorf("DecodeConfig: %v", err)
+	}
+	if imgCfg.Width > setting.AvatarMaxWidth {
+		return fmt.Errorf("Image width is to large: %d > %d", imgCfg.Width, setting.AvatarMaxWidth)
+	}
+	if imgCfg.Height > setting.AvatarMaxHeight {
+		return fmt.Errorf("Image height is to large: %d > %d", imgCfg.Height, setting.AvatarMaxHeight)
+	}
+
 	img, _, err := image.Decode(bytes.NewReader(data))
 	if err != nil {
 		return fmt.Errorf("Decode: %v", err)
diff --git a/modules/setting/setting.go b/modules/setting/setting.go
index cf9f59853bb6c..a5f4457f33374 100644
--- a/modules/setting/setting.go
+++ b/modules/setting/setting.go
@@ -341,6 +341,8 @@ var (
 
 	// Picture settings
 	AvatarUploadPath      string
+	AvatarMaxWidth        int
+	AvatarMaxHeight       int
 	GravatarSource        string
 	GravatarSourceURL     *url.URL
 	DisableGravatar       bool
@@ -1024,6 +1026,8 @@ func NewContext() {
 	if !filepath.IsAbs(AvatarUploadPath) {
 		AvatarUploadPath = path.Join(AppWorkPath, AvatarUploadPath)
 	}
+	AvatarMaxWidth = sec.Key("AVATAR_MAX_WIDTH").MustInt(4096)
+	AvatarMaxHeight = sec.Key("AVATAR_MAX_HEIGHT").MustInt(3072)
 	switch source := sec.Key("GRAVATAR_SOURCE").MustString("gravatar"); source {
 	case "duoshuo":
 		GravatarSource = "http://gravatar.duoshuo.com/avatar/"