diff --git a/luci-app-passwall2/Makefile b/luci-app-passwall2/Makefile
index 63f0c792e..ebaffbc62 100644
--- a/luci-app-passwall2/Makefile
+++ b/luci-app-passwall2/Makefile
@@ -7,7 +7,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=luci-app-passwall2
 PKG_VERSION:=26.10.20
-PKG_RELEASE:=150
+PKG_RELEASE:=151
 PKG_PO_VERSION:=$(PKG_VERSION)
 
 PKG_CONFIG_DEPENDS:= \
diff --git a/luci-app-passwall2/po/fa/passwall2.po b/luci-app-passwall2/po/fa/passwall2.po
index 10762bb58..06bb1f226 100644
--- a/luci-app-passwall2/po/fa/passwall2.po
+++ b/luci-app-passwall2/po/fa/passwall2.po
@@ -2291,6 +2291,9 @@ msgstr "خطای تأیید اندازه فایل دانلود شده. اندا
 msgid "%s SHA256 verification information is invalid. Update failed."
 msgstr "اطلاعات تأیید SHA256 برای %s نامعتبر است. به‌روزرسانی ناموفق بود."
 
+msgid "%s file format verification failed. Update failed."
+msgstr "قالب فایل %s نامعتبر است. به‌روزرسانی ناموفق بود."
+
 msgid "Downloaded file is empty or an error occurred while reading it."
 msgstr "فایل دانلود شده خالی است یا خطایی هنگام خواندن آن رخ داده است."
 
diff --git a/luci-app-passwall2/po/ru/passwall2.po b/luci-app-passwall2/po/ru/passwall2.po
index fa79867c2..e5d8985b4 100644
--- a/luci-app-passwall2/po/ru/passwall2.po
+++ b/luci-app-passwall2/po/ru/passwall2.po
@@ -2292,6 +2292,9 @@ msgstr "Ошибка проверки размера файла. Исходны
 msgid "%s SHA256 verification information is invalid. Update failed."
 msgstr "Недопустимые данные проверки SHA256 для %s. Обновление не выполнено."
 
+msgid "%s file format verification failed. Update failed."
+msgstr "Ошибка проверки формата файла %s. Обновление не выполнено."
+
 msgid "Downloaded file is empty or an error occurred while reading it."
 msgstr "Загруженный файл пуст или произошла ошибка при чтении."
 
diff --git a/luci-app-passwall2/po/zh-cn/passwall2.po b/luci-app-passwall2/po/zh-cn/passwall2.po
index 09d0955e4..da2002425 100644
--- a/luci-app-passwall2/po/zh-cn/passwall2.po
+++ b/luci-app-passwall2/po/zh-cn/passwall2.po
@@ -2277,6 +2277,9 @@ msgstr "下载文件大小校验出错，原始文件大小 %sB，下载文件
 msgid "%s SHA256 verification information is invalid. Update failed."
 msgstr "%s SHA256 校验信息无效，更新失败。"
 
+msgid "%s file format verification failed. Update failed."
+msgstr "%s 文件格式校验错误，更新失败。"
+
 msgid "Downloaded file is empty or an error occurred while reading it."
 msgstr "下载的文件为空或读取文件时发生错误。"
 
diff --git a/luci-app-passwall2/po/zh-tw/passwall2.po b/luci-app-passwall2/po/zh-tw/passwall2.po
index dfdbbf4d6..9ec22971e 100644
--- a/luci-app-passwall2/po/zh-tw/passwall2.po
+++ b/luci-app-passwall2/po/zh-tw/passwall2.po
@@ -2283,6 +2283,9 @@ msgstr "下載檔案大小校驗出錯，原始檔案大小 %sB，下載檔案
 msgid "%s SHA256 verification information is invalid. Update failed."
 msgstr "%s SHA256 校驗資訊無效，更新失敗。"
 
+msgid "%s file format verification failed. Update failed."
+msgstr "%s 檔案格式校驗錯誤，更新失敗。"
+
 msgid "Downloaded file is empty or an error occurred while reading it."
 msgstr "下載的文件為空或讀取文件時發生錯誤。"
 
diff --git a/luci-app-passwall2/root/usr/share/passwall2/rule_update.lua b/luci-app-passwall2/root/usr/share/passwall2/rule_update.lua
index d854c95cb..d5e98bb93 100755
--- a/luci-app-passwall2/root/usr/share/passwall2/rule_update.lua
+++ b/luci-app-passwall2/root/usr/share/passwall2/rule_update.lua
@@ -109,6 +109,98 @@ local function non_file_check(file_path, header_content)
 	return false
 end
 
+-- Check every Geo category boundary and sample its first rule to identify the format.
+local function validate_geo_file(file_path, geo_type)
+	if geo_type ~= "geoip" and geo_type ~= "geosite" then return false end
+	local file = io.open(file_path, "rb")
+	if not file then return false end
+	local size = file:seek("end")
+	if not size or size == 0 or not file:seek("set", 0) then file:close(); return false end
+	local pos, rules = 0, 0
+	-- Use the file's read buffer and seek past skipped content without an extra buffer.
+	local function skip(length, limit)
+		assert(length <= limit - pos)
+		pos = pos + length
+		assert(file:seek("set", pos))
+	end
+	-- Without a numeric limit, only validate and skip varints to avoid precision loss for 64-bit attributes.
+	local function varint(limit, maximum)
+		local value, factor = 0, 1
+		for i = 1, 10 do
+			assert(pos < limit)
+			local byte = assert(file:read(1)):byte()
+			pos = pos + 1
+			assert(i < 10 or byte <= 1)
+			if maximum then
+				local digit = byte % 128
+				assert(digit <= math.floor((maximum - value) / factor))
+				value = value + digit * factor
+			end
+			if byte < 128 then return value end
+			factor = factor * 128
+		end
+		error(false)
+	end
+	-- Field definitions: wire type, optional child message type, optional numeric limit.
+	local schema = {
+		list = {{2, geo_type}},
+		geoip = {{2}, {2, "cidr"}, {0}},
+		geosite = {{2}, {2, "domain"}},
+		cidr = {{2}, {0, nil, 4294967295}},
+		domain = {{0, nil, 3}, {2}, {2, "attribute"}},
+		attribute = {{2}, {0}, {0}}
+	}
+	local parse
+	parse = function(kind, limit)
+		local values, entries = {}, 0
+		local is_entry = kind == "geoip" or kind == "geosite"
+		while pos < limit do
+			if is_entry and values[1] and values[1] > 0 and entries > 0 then
+				skip(limit - pos, limit)
+				return
+			end
+			local tag = varint(limit, 4294967295)
+			local field, wire = math.floor(tag / 8), tag % 8
+			local spec = schema[kind][field]
+			assert(field > 0 and (not spec or wire == spec[1]))
+			local value
+			if wire == 0 then
+				value = varint(limit, spec and spec[3])
+			elseif wire == 2 then
+				value = varint(limit, limit - pos)
+				assert(value <= limit - pos)
+				if spec and spec[2] and not (is_entry and entries > 0) then
+					parse(spec[2], pos + value)
+				else
+					skip(value, limit)
+				end
+				if spec and spec[2] then entries = entries + 1 end
+			elseif wire == 1 or wire == 5 then
+				skip(wire == 1 and 8 or 4, limit)
+			else
+				-- Geo files do not use Protobuf group fields.
+				error(false)
+			end
+			if spec then values[field] = value end
+		end
+		if kind == "list" then
+			assert(entries > 0 and rules > 0)
+		elseif kind == "geoip" or kind == "geosite" or kind == "attribute" then
+			assert(values[1] and values[1] > 0)
+		elseif kind == "cidr" then
+			assert(values[1] == 4 or values[1] == 16)
+			assert((values[2] or 0) <= (values[1] == 4 and 32 or 128))
+			rules = rules + 1
+		elseif kind == "domain" then
+			assert(values[2] and values[2] > 0)
+			rules = rules + 1
+		end
+	end
+	local valid = pcall(parse, "list", size)
+	file:close()
+	return valid
+end
+
 local function fetch_geofile(geo_name, geo_type, url)
 	local tmp_path = "/tmp/" .. geo_name
 	local asset_path = asset_location .. geo_name
@@ -160,6 +252,10 @@ local function fetch_geofile(geo_name, geo_type, url)
 				return 1
 			end
 		else
+			if not validate_geo_file(tmp_path, geo_type) then
+				log(1, api.i18n.translatef("%s file format verification failed. Update failed.", geo_type))
+				return 1
+			end
 			if fs.access(asset_path) and sys.call(string.format("cmp -s %s %s", tmp_path, asset_path)) == 0 then
 				log(1, api.i18n.translatef("%s version is the same and does not need to be updated.", geo_type))
 				return 0