fix(sec): enforce repository token scope on repo feeds

Repository RSS/Atom feed handlers opt into PAT basic auth but never
checked the token's scope, so a token without repository scope could read
private repository commit history and activity via the feeds, while the
sibling download endpoints correctly denied it.

Add a token scope check mirroring checkDownloadTokenScope to every
repo-content feed function (branch, file, repo activity, releases/tags).

Assisted-by: Claude:claude-opus-4-8

routers/web/feed/branch.go

@@ -15,6 +15,9 @@ import (
 
 // ShowBranchFeed shows tags and/or releases on the repo as RSS / Atom feed
 func ShowBranchFeed(ctx *context.Context, repo *repo.Repository, formatType string) {
+	if !checkRepoFeedTokenScope(ctx) {
+		return
+	}
 	var commits []*git.Commit
 	var err error
 	if ctx.Repo.Commit != nil {

routers/web/feed/file.go

@@ -16,6 +16,9 @@ import (
 
 // ShowFileFeed shows tags and/or releases on the repo as RSS / Atom feed
 func ShowFileFeed(ctx *context.Context, repo *repo.Repository, formatType string) {
+	if !checkRepoFeedTokenScope(ctx) {
+		return
+	}
 	fileName := ctx.Repo.TreePath
 	if len(fileName) == 0 {
 		return

routers/web/feed/release.go

@@ -15,6 +15,9 @@ import (
 
 // shows tags and/or releases on the repo as RSS / Atom feed
 func ShowReleaseFeed(ctx *context.Context, repo *repo_model.Repository, isReleasesOnly bool, formatType string) {
+	if !checkRepoFeedTokenScope(ctx) {
+		return
+	}
 	releases, err := db.Find[repo_model.Release](ctx, repo_model.FindReleasesOptions{
 		IncludeTags: !isReleasesOnly,
 		RepoID:      ctx.Repo.Repository.ID,

routers/web/feed/render.go

@@ -4,9 +4,18 @@
 package feed
 
 import (
+	auth_model "gitea.dev/models/auth"
 	"gitea.dev/services/context"
 )
 
+// checkRepoFeedTokenScope ensures an API token has repository read scope before a
+// feed serves private repository content, mirroring checkDownloadTokenScope for
+// downloads. Returns false (and writes the response) when the token is denied.
+func checkRepoFeedTokenScope(ctx *context.Context) bool {
+	context.CheckRepoScopedToken(ctx, ctx.Repo.Repository, auth_model.Read)
+	return !ctx.Written()
+}
+
 // RenderBranchFeed render format for branch or file
 func RenderBranchFeed(ctx *context.Context, feedType string) {
 	if ctx.Repo.TreePath == "" {

routers/web/feed/repo.go

@@ -16,6 +16,9 @@ import (
 
 // ShowRepoFeed shows user activity on the repo as RSS / Atom feed
 func ShowRepoFeed(ctx *context.Context, repo *repo_model.Repository, formatType string) {
+	if !checkRepoFeedTokenScope(ctx) {
+		return
+	}
 	actions, _, err := feed_service.GetFeeds(ctx, activities_model.GetFeedsOptions{
 		RequestedRepo:  repo,
 		Actor:          ctx.Doer,

tests/integration/feed_repo_test.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"testing"
 
+	auth_model "gitea.dev/models/auth"
 	"gitea.dev/tests"
 
 	"github.com/stretchr/testify/assert"
@@ -33,3 +34,41 @@ func TestFeedRepo(t *testing.T) {
 		assert.NotEmpty(t, rss.Channel.Items[0].PubDate)
 	})
 }
+
+// TestFeedRepoContentTokenScopes ensures repository feed endpoints enforce the
+// repository token scope, so a PAT without repository scope cannot read private
+// repository commit/activity data through RSS/Atom feeds.
+func TestFeedRepoContentTokenScopes(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	// user2/repo2 is a private repository owned by user2
+	ownerReadToken := getUserToken(t, "user2", auth_model.AccessTokenScopeReadRepository)
+	miscToken := getUserToken(t, "user2", auth_model.AccessTokenScopeReadMisc)
+
+	urls := []string{
+		"/user2/repo2.rss",
+		"/user2/repo2.atom",
+		"/user2/repo2/rss/branch/master",
+		"/user2/repo2/atom/branch/master",
+		"/user2/repo2/rss/branch/master/README.md",
+		"/user2/repo2/tags.rss",
+		"/user2/repo2/tags.atom",
+		"/user2/repo2/releases.rss",
+		"/user2/repo2/releases.atom",
+	}
+
+	for _, url := range urls {
+		t.Run(url, func(t *testing.T) {
+			// feed routes only accept basic auth, so authenticate as the advisory PoC does (user:token)
+			reqDenied := NewRequest(t, "GET", url)
+			reqDenied.SetBasicAuth("user2", miscToken)
+			// a token without repository scope must be denied
+			MakeRequest(t, reqDenied, http.StatusForbidden)
+
+			reqAllowed := NewRequest(t, "GET", url)
+			reqAllowed.SetBasicAuth("user2", ownerReadToken)
+			// a token with repository read scope is allowed
+			MakeRequest(t, reqAllowed, http.StatusOK)
+		})
+	}
+}