diff --git a/CHANGELOG.md b/CHANGELOG.md
index b63a33dc..6195f18c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+# [3.3.7] - 2026-10-24
+
+3.3.7 只改应用内更新，为 4.0 正式版做准备。
+
+- **变更（应用内更新）**：「软件更新」只提供与当前镜像主版本相同的版本（3.x），稳定版与测试版渠道都是如此。4.0 的更新包要求 4.0 镜像，在 3.3 镜像上无法应用；升级到 4.0 请更换镜像标签，步骤见 [从 3.3 升级到 4.0](https://www.autobangumi.org/deploy/upgrade-4.0)
+
 # [3.3.6] - 2026-09-19
 
 3.3.6 是问题修复版本，修复 3.3.5 发布后报告的 RSS 匹配、网络、解析与部署问题。
diff --git a/backend/pyproject.toml b/backend/pyproject.toml
index de300f94..52973ac6 100644
--- a/backend/pyproject.toml
+++ b/backend/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "auto-bangumi"
-version = "3.3.6"
+version = "3.3.7"
 description = "AutoBangumi - Automated anime download manager"
 requires-python = ">=3.13"
 dependencies = [
diff --git a/backend/src/module/update/updater.py b/backend/src/module/update/updater.py
index 489abb54..196429a1 100644
--- a/backend/src/module/update/updater.py
+++ b/backend/src/module/update/updater.py
@@ -217,7 +217,7 @@ class Updater:
 
     async def _fetch_releases(self) -> list[dict]:
         client = await self._get_client()
-        url = f"{_API_BASE}/repos/{self.owner}/{self.repo}/releases?per_page=20"
+        url = f"{_API_BASE}/repos/{self.owner}/{self.repo}/releases?per_page=100"
         resp = await client.get(url, headers=_API_HEADERS)
         resp.raise_for_status()
         data = resp.json()
@@ -269,6 +269,9 @@ class Updater:
         return bundle_url, sha_url, sig_url
 
     def _pick_release(self, releases: list[dict], channel: str) -> Optional[dict]:
+        # 只提供与镜像同一主版本的更新：下一个主版本的更新包要求新镜像
+        # （min_image_version），只能更换镜像标签升级
+        image = _parse_semver(self.image_version)
         candidates: list[tuple[semver.VersionInfo, dict]] = []
         for rel in releases:
             if rel.get("draft"):
@@ -278,6 +281,8 @@ class Updater:
             ver = _parse_semver(rel.get("tag_name") or "")
             if ver is None:
                 continue
+            if image is not None and ver.major != image.major:
+                continue
             candidates.append((ver, rel))
         if not candidates:
             return None
diff --git a/backend/src/test/test_update.py b/backend/src/test/test_update.py
index f6fadf5b..77732462 100644
--- a/backend/src/test/test_update.py
+++ b/backend/src/test/test_update.py
@@ -233,6 +233,22 @@ class TestCheckUpdate:
         assert res.is_prerelease is True
         assert res.has_update is True
 
+    @pytest.mark.parametrize(
+        "channel, expected", [("stable", "3.3.7"), ("beta", "3.3.8-beta.1")]
+    )
+    def test_next_major_release_is_not_offered(self, tmp_path, channel, expected):
+        """4.x 的更新包要求 4.x 镜像，3.x 镜像只能更换镜像标签升级。"""
+        releases = [
+            {"tag_name": tag, "prerelease": "beta" in tag}
+            for tag in ("4.0.0", "4.0.0-beta.9", "3.3.8-beta.1", "3.3.7")
+        ]
+        up = Updater(
+            root=tmp_path / "u", current_version="3.3.6", image_version="3.3.6"
+        )
+        picked = up._pick_release(releases, channel)
+        assert picked is not None
+        assert picked["tag_name"] == expected
+
     @pytest.mark.asyncio
     async def test_no_update_when_current_is_latest(self, tmp_path, bundle):
         data, sha = bundle
diff --git a/backend/uv.lock b/backend/uv.lock
index 8a32c736..f6fe9952 100644
--- a/backend/uv.lock
+++ b/backend/uv.lock
@@ -1,5 +1,5 @@
 version = 1
-revision = 3
+revision = 5
 requires-python = ">=3.13"
 resolution-markers = [
     "python_full_version >= '3.15'",
@@ -125,7 +125,7 @@ wheels = [
 
 [[package]]
 name = "auto-bangumi"
-version = "3.3.6"
+version = "3.3.7"
 source = { virtual = "." }
 dependencies = [
     { name = "aiosqlite" },
diff --git a/docs/changelog/3.3.md b/docs/changelog/3.3.md
index 1ef2686a..f866fb03 100644
--- a/docs/changelog/3.3.md
+++ b/docs/changelog/3.3.md
@@ -2,6 +2,12 @@
 
 3.3 is the largest AutoBangumi release in a while: a fully async backend architecture, aria2 promoted to a first-class download backend, movie/OVA/special support, per-bangumi release preferences, a hardened security stack, and a WebUI that updates over SSE instead of polling. REST API behavior is backward-compatible; existing databases upgrade automatically through schema v24.
 
+## 3.3.7 — In-app update stays on 3.x
+
+3.3.7 changes only the in-app update, to prepare for the 4.0 stable release.
+
+- **In-app update:** Software Update now offers only versions with the same major version as the image (3.x), on the stable and the beta channel. A 4.0 update bundle needs a 4.0 image and cannot be applied on a 3.3 image. To upgrade to 4.0, change the image tag. See [Upgrade from 3.3 to 4.0](https://www.autobangumi.org/en/deploy/upgrade-4.0).
+
 ## 3.3.6 — RSS matching, proxy, parser, and deployment fixes
 
 3.3.6 is a bugfix release for issues reported after 3.3.5.