fix: enforce public-only token scope and harden push options / locale parsing (#38323)

- **Locale DoS:** the `Locale` middleware passed the raw
`Accept-Language` header to `ParseAcceptLanguage`, whose guard only
counts `-` while the scanner aliases `_` to `-` — a large `_`-separated
header on an unauthenticated request burned CPU. The header is now
length-bounded before parsing.
- **Public-only token scope:** `GET /teams/{id}/repos`,
`.../repos/{org}/{repo}`, `/teams/{id}/activities/feeds`, and
`/users/{username}/orgs/{org}/permissions` still returned private
repo/activity/permission data to a public-only token. They now filter
via `TokenCanAccessRepo` / `ApplyPublicOnly` and reject non-public org
permissions.
- **Push-option visibility:** `repo.private` / `repo.template` push
options were applied to any existing repo, letting an owner/admin
silently flip visibility bypassing audit, webhooks, and notifications.
They are now honored only on push-to-create.

models/repo/org_repo.go

@@ -31,18 +31,28 @@ func GetOrgRepositoryIDs(ctx context.Context, orgID int64) (repoIDs []int64, _ e
 type SearchTeamRepoOptions struct {
 	db.ListOptions
 	TeamID int64
+	// PublicOnly restricts the result (and count) to non-private repositories.
+	PublicOnly bool
+}
+
+func (opts *SearchTeamRepoOptions) toCond() builder.Cond {
+	cond := builder.NewCond()
+	if opts.TeamID > 0 {
+		cond = cond.And(builder.In("id",
+			builder.Select("repo_id").
+				From("team_repo").
+				Where(builder.Eq{"team_id": opts.TeamID}),
+		))
+	}
+	if opts.PublicOnly {
+		cond = cond.And(builder.Eq{"is_private": false})
+	}
+	return cond
 }
 
 // GetTeamRepositories returns paginated repositories in team of organization.
 func GetTeamRepositories(ctx context.Context, opts *SearchTeamRepoOptions) (RepositoryList, error) {
-	sess := db.GetEngine(ctx)
-	if opts.TeamID > 0 {
-		sess = sess.In("id",
-			builder.Select("repo_id").
-				From("team_repo").
-				Where(builder.Eq{"team_id": opts.TeamID}),
-		)
-	}
+	sess := db.GetEngine(ctx).Where(opts.toCond())
 	if opts.PageSize > 0 {
 		sess.Limit(opts.PageSize, (opts.Page-1)*opts.PageSize)
 	}
@@ -51,6 +61,11 @@ func GetTeamRepositories(ctx context.Context, opts *SearchTeamRepoOptions) (Repo
 		Find(&repos)
 }
 
+// CountTeamRepositories returns the number of repositories in team of organization matching opts.
+func CountTeamRepositories(ctx context.Context, opts *SearchTeamRepoOptions) (int64, error) {
+	return db.GetEngine(ctx).Where(opts.toCond()).Count(new(Repository))
+}
+
 // AccessibleReposEnvironment operations involving the repositories that are
 // accessible to a particular user
 type AccessibleReposEnvironment interface {

modules/web/middleware/locale.go

@@ -12,6 +12,24 @@ import (
 	"golang.org/x/text/language"
 )
 
+// maxAcceptLanguageLen bounds the Accept-Language header before it reaches
+// language.ParseAcceptLanguage. That parser has quadratic-time behavior on long
+// malformed inputs, and its built-in guard only counts "-" separators while the
+// scanner treats "_" as an alias for "-", so a "_"-heavy header slips past the
+// guard and burns CPU. Only the leading (highest-priority) languages are used, so
+// truncating a longer header is safe.
+const maxAcceptLanguageLen = 200
+
+// parseAcceptLanguage parses the Accept-Language header after bounding its length
+// to avoid a quadratic-time DoS on attacker-controlled input.
+func parseAcceptLanguage(header string) []language.Tag {
+	if len(header) > maxAcceptLanguageLen {
+		header = header[:maxAcceptLanguageLen]
+	}
+	tags, _, _ := language.ParseAcceptLanguage(header)
+	return tags
+}
+
 // Locale handle locale
 func Locale(resp http.ResponseWriter, req *http.Request) translation.Locale {
 	// 1. Check URL arguments.
@@ -35,7 +53,7 @@ func Locale(resp http.ResponseWriter, req *http.Request) translation.Locale {
 	// 3. Get language information from 'Accept-Language'.
 	// The first element in the list is chosen to be the default language automatically.
 	if len(lang) == 0 {
-		tags, _, _ := language.ParseAcceptLanguage(req.Header.Get("Accept-Language"))
+		tags := parseAcceptLanguage(req.Header.Get("Accept-Language"))
 		tag := translation.Match(tags...)
 		lang = tag.String()
 	}

modules/web/middleware/locale_test.go

@@ -0,0 +1,27 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package middleware
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseAcceptLanguage(t *testing.T) {
+	// a normal header is parsed and its leading language preserved
+	tags := parseAcceptLanguage("de-DE,de;q=0.9,en;q=0.8")
+	assert.NotEmpty(t, tags)
+	assert.Equal(t, "de-DE", tags[0].String())
+
+	// an oversized "_"-separated header would drive ParseAcceptLanguage into its
+	// quadratic-time path (the built-in guard only counts "-"); the length bound
+	// keeps the input passed to the parser small so it cannot be used for a DoS.
+	malicious := strings.Repeat("_aaaaaaaaa", 1<<16) // ~640 KiB, zero "-" characters
+	assert.Greater(t, len(malicious), maxAcceptLanguageLen)
+	tags = parseAcceptLanguage(malicious)
+	// no panic / hang, and nothing meaningful is parsed out of the garbage
+	assert.Empty(t, tags)
+}

routers/api/v1/org/org.go

@@ -145,6 +145,13 @@ func GetUserOrgsPermissions(ctx *context.APIContext) {
 
 	op := api.OrganizationPermissions{}
 
+	// A public-only token must not disclose membership/permission details of a
+	// non-public org, even for the token owner's own private orgs.
+	if ctx.PublicOnly && !o.Visibility.IsPublic() {
+		ctx.APIErrorNotFound()
+		return
+	}
+
 	if !organization.HasOrgOrUserVisible(ctx, o, ctx.Doer) {
 		ctx.APIErrorNotFound()
 		return

routers/api/v1/org/team.go

@@ -567,10 +567,20 @@ func GetTeamRepos(ctx *context.APIContext) {
 
 	team := ctx.Org.Team
 	listOptions := utils.GetListOptions(ctx)
-	teamRepos, err := repo_model.GetTeamRepositories(ctx, &repo_model.SearchTeamRepoOptions{
+	// A public-only token must not expose (or count) private repos, even when the
+	// doer owning the token otherwise has access to them, so filter them out at the
+	// query level to keep the returned page and the total-count header consistent.
+	searchOpts := &repo_model.SearchTeamRepoOptions{
 		ListOptions: listOptions,
 		TeamID:      team.ID,
-	})
+		PublicOnly:  ctx.PublicOnly,
+	}
+	teamRepos, err := repo_model.GetTeamRepositories(ctx, searchOpts)
+	if err != nil {
+		ctx.APIErrorInternal(err)
+		return
+	}
+	count, err := repo_model.CountTeamRepositories(ctx, searchOpts)
 	if err != nil {
 		ctx.APIErrorInternal(err)
 		return
@@ -584,14 +594,16 @@ func GetTeamRepos(ctx *context.APIContext) {
 		}
 		// A team's repo list is reachable by non-team-members through the team's
 		// visibility tier, so never expose repos (incl. their names) the doer
-		// cannot access.
+		// cannot access. This per-repo visibility trim can't be expressed in the
+		// SQL count above without regressing per-unit public access, so for such
+		// non-members the total-count header may be a small upper bound.
 		if !permission.HasAnyUnitAccessOrPublicAccess() {
 			continue
 		}
 		repos = append(repos, convert.ToRepo(ctx, repo, permission))
 	}
-	ctx.SetLinkHeader(int64(team.NumRepos), listOptions.PageSize)
-	ctx.SetTotalCountHeader(int64(team.NumRepos))
+	ctx.SetLinkHeader(count, listOptions.PageSize)
+	ctx.SetTotalCountHeader(count)
 	ctx.JSON(http.StatusOK, repos)
 }
 
@@ -630,6 +642,12 @@ func GetTeamRepo(ctx *context.APIContext) {
 		return
 	}
 
+	// A public-only token must not confirm the existence of a private repo.
+	if !ctx.TokenCanAccessRepo(repo) {
+		ctx.APIErrorNotFound()
+		return
+	}
+
 	if !organization.HasTeamRepo(ctx, ctx.Org.Team.OrgID, ctx.Org.Team.ID, repo.ID) {
 		ctx.APIErrorNotFound()
 		return
@@ -889,6 +907,8 @@ func ListTeamActivityFeeds(ctx *context.APIContext) {
 		Date:           ctx.FormString("date"),
 		ListOptions:    listOptions,
 	}
+	// A public-only token must not receive private activity entries.
+	opts.ApplyPublicOnly(ctx.PublicOnly)
 
 	feeds, count, err := feed_service.GetFeeds(ctx, opts)
 	if err != nil {

routers/private/hook_post_receive.go

@@ -160,10 +160,17 @@ func hookPostReceiveUpdateRepoByOptions(ctx *gitea_context.PrivateContext, opts
 			return false
 		}
 
-		// FIXME: these options are not quite right, for example: changing visibility should do more works than just setting the is_private flag
-		// These options should only be used for "push-to-create"
+		// Only honor these options while the repo is still empty (the push-to-create
+		// case). On a populated repo a bare "git push -o repo.private=..." would
+		// silently flip visibility, bypassing the audit log, webhooks and notifications.
+		if !repo.IsEmpty {
+			return true
+		}
+
+		// The repo is empty and being initialized by this push, so there is no
+		// dependent state (webhooks, notifications, visibility fan-out) to reconcile
+		// yet; setting the flags directly is sufficient in this push-to-create case.
 		if isPrivate.Has() && repo.IsPrivate != isPrivate.Value() {
-			// TODO: it needs to do more work
 			repo.IsPrivate = isPrivate.Value()
 			if err = repo_model.UpdateRepositoryColsNoAutoTime(ctx, repo, "is_private"); err != nil {
 				log.Error("failed to update repo is_private: %v", err)

tests/integration/api_public_only_test.go

@@ -5,9 +5,14 @@ package integration
 
 import (
 	"net/http"
+	"strconv"
 	"testing"
 
 	auth_model "gitea.dev/models/auth"
+	"gitea.dev/models/organization"
+	repo_model "gitea.dev/models/repo"
+	"gitea.dev/models/unittest"
+	user_model "gitea.dev/models/user"
 	api "gitea.dev/modules/structs"
 	"gitea.dev/tests"
 
@@ -95,6 +100,59 @@ func TestAPIActivityFeedsPublicOnly(t *testing.T) {
 	assertPublicActivitiesOnly(t, activities)
 }
 
+func TestAPIOrgPermissionsPublicOnly(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	// user2 is a member of the private org private_org35
+	org := unittest.AssertExistsAndLoadBean(t, &user_model.User{Name: "private_org35"})
+
+	// a full org-scoped token can read the membership permissions
+	token := getUserToken(t, "user2", auth_model.AccessTokenScopeReadUser, auth_model.AccessTokenScopeReadOrganization)
+	req := NewRequestf(t, "GET", "/api/v1/users/user2/orgs/%s/permissions", org.Name).AddTokenAuth(token)
+	MakeRequest(t, req, http.StatusOK)
+
+	// a public-only token must not disclose permissions for a private org
+	publicToken := getUserToken(t, "user2", auth_model.AccessTokenScopeReadUser, auth_model.AccessTokenScopeReadOrganization, auth_model.AccessTokenScopePublicOnly)
+	req = NewRequestf(t, "GET", "/api/v1/users/user2/orgs/%s/permissions", org.Name).AddTokenAuth(publicToken)
+	MakeRequest(t, req, http.StatusNotFound)
+}
+
+func TestAPITeamReposPublicOnly(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	// team 1 (Owners of org3) has access to the private repos org3/repo3 and org3/repo5
+	team := unittest.AssertExistsAndLoadBean(t, &organization.Team{ID: 1})
+	privateRepo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 3})
+	privateRepo2 := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 5})
+
+	// a full org+repo scoped token sees the private repos
+	token := getUserToken(t, "user2", auth_model.AccessTokenScopeReadOrganization, auth_model.AccessTokenScopeReadRepository)
+	req := NewRequestf(t, "GET", "/api/v1/teams/%d/repos", team.ID).AddTokenAuth(token)
+	resp := MakeRequest(t, req, http.StatusOK)
+	repos := DecodeJSON(t, resp, []api.Repository{})
+	assert.Contains(t, repoNames(repos), privateRepo.FullName())
+
+	// a public-only token must not receive any private repo
+	publicToken := getUserToken(t, "user2", auth_model.AccessTokenScopeReadOrganization, auth_model.AccessTokenScopeReadRepository, auth_model.AccessTokenScopePublicOnly)
+	req = NewRequestf(t, "GET", "/api/v1/teams/%d/repos", team.ID).AddTokenAuth(publicToken)
+	resp = MakeRequest(t, req, http.StatusOK)
+	repos = DecodeJSON(t, resp, []api.Repository{})
+	for _, repo := range repos {
+		assert.False(t, repo.Private)
+	}
+	assert.NotContains(t, repoNames(repos), privateRepo.FullName())
+	assert.NotContains(t, repoNames(repos), privateRepo2.FullName())
+	// the total-count header must match the filtered page, otherwise it leaks the
+	// number of hidden private repos
+	assert.Equal(t, strconv.Itoa(len(repos)), resp.Header().Get("X-Total-Count"))
+
+	// the single-repo endpoint must not confirm a private repo for a public-only token
+	req = NewRequestf(t, "GET", "/api/v1/teams/%d/repos/%s", team.ID, privateRepo.FullName()).AddTokenAuth(token)
+	MakeRequest(t, req, http.StatusOK)
+	req = NewRequestf(t, "GET", "/api/v1/teams/%d/repos/%s", team.ID, privateRepo.FullName()).AddTokenAuth(publicToken)
+	MakeRequest(t, req, http.StatusNotFound)
+}
+
 func assertPublicActivitiesOnly(t *testing.T, activities []api.Activity) {
 	t.Helper()
 

tests/integration/git_push_test.go

@@ -11,6 +11,7 @@ import (
 	auth_model "gitea.dev/models/auth"
 	"gitea.dev/models/db"
 	git_model "gitea.dev/models/git"
+	repo_model "gitea.dev/models/repo"
 	"gitea.dev/models/unittest"
 	user_model "gitea.dev/models/user"
 	"gitea.dev/modules/git"
@@ -140,6 +141,43 @@ func testGitPush(t *testing.T, u *url.URL) {
 	})
 }
 
+func TestGitPushVisibilityOption(t *testing.T) {
+	onGiteaRun(t, func(t *testing.T, u *url.URL) {
+		user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
+		repo, err := repo_service.CreateRepository(t.Context(), user, user, repo_service.CreateRepoOptions{
+			Name:          "repo-visibility-option",
+			AutoInit:      false,
+			DefaultBranch: "master",
+			IsPrivate:     false,
+		})
+		require.NoError(t, err)
+		require.NotEmpty(t, repo)
+
+		gitPath := t.TempDir()
+		doGitInitTestRepository(gitPath)(t)
+
+		oldPath, oldUser := u.Path, u.User
+		defer func() { u.Path, u.User = oldPath, oldUser }()
+		u.Path = repo.FullName() + ".git"
+		u.User = url.UserPassword(user.LowerName, userPassword)
+		doGitAddRemote(gitPath, "origin", u)(t)
+
+		// The first push into an empty repository is a "push-to-create", so the
+		// repo.private push option is honored to set the initial visibility.
+		doGitPushTestRepository(gitPath, "origin", "master", "-o", "repo.private=true")(t)
+		repo = unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: repo.ID})
+		assert.True(t, repo.IsPrivate, "repo.private option should apply on push-to-create")
+
+		// The repository is now populated; a later push must NOT silently flip
+		// visibility, otherwise a repo admin could change it bypassing the audit
+		// trail, webhooks, and notifications a proper settings change would fire.
+		doGitCreateBranch(gitPath, "branch2")(t)
+		doGitPushTestRepository(gitPath, "origin", "branch2", "-o", "repo.private=false")(t)
+		repo = unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: repo.ID})
+		assert.True(t, repo.IsPrivate, "repo.private option must be ignored on an existing repository")
+	})
+}
+
 func runTestGitPush(t *testing.T, u *url.URL, gitOperation func(t *testing.T, gitPath string) (pushed, deleted []string)) {
 	user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
 	repo, err := repo_service.CreateRepository(t.Context(), user, user, repo_service.CreateRepoOptions{