diff --git a/routers/web/repo/issue_new.go b/routers/web/repo/issue_new.go
index b6422900cb..57786dd7d7 100644
--- a/routers/web/repo/issue_new.go
+++ b/routers/web/repo/issue_new.go
@@ -146,6 +146,7 @@ func NewIssue(ctx *context.Context) {
 	}
 
 	ctx.Data["HasIssuesOrPullsWritePermission"] = ctx.Repo.Permission.CanWrite(unit.TypeIssues)
+	ctx.Data["IsIssuePoster"] = true // the current user will be the poster of the new issue
 
 	if !issueConfig.BlankIssuesEnabled && hasTemplates && !templateLoaded {
 		// The "issues/new" and "issues/new/choose" share the same query parameters "project" and "milestone", if blank issues are disabled, just redirect to the "issues/choose" page with these parameters.
diff --git a/templates/repo/issue/branch_selector_field.tmpl b/templates/repo/issue/branch_selector_field.tmpl
index 2f3e792d64..7d2dcfd9f7 100644
--- a/templates/repo/issue/branch_selector_field.tmpl
+++ b/templates/repo/issue/branch_selector_field.tmpl
@@ -14,14 +14,15 @@ Still needs to figure out:
 * Is "GitHub-like development sidebar (`#31899`)" good enough (or better) for your usage?
 */}}
 {{if and (not .Issue.IsPull) (not .PageIsComparePull)}}
+{{$canChangeRef := or .IsIssuePoster .HasIssuesOrPullsWritePermission}}
 <input id="ref_selector" name="ref" type="hidden" value="{{.Reference}}">
-<div class="ui dropdown select-branch branch-selector-dropdown ellipsis-text-items {{if not .HasIssuesOrPullsWritePermission}}disabled{{end}}"
+<div class="ui dropdown select-branch branch-selector-dropdown ellipsis-text-items {{if not $canChangeRef}}disabled{{end}}"
 	data-no-results="{{ctx.Locale.Tr "no_results_found"}}"
-	{{if and .Issue (or .IsIssueWriter .HasIssuesOrPullsWritePermission)}}data-url-update-issueref="{{$.RepoLink}}/issues/{{.Issue.Index}}/ref"{{end}}
+	{{if and .Issue $canChangeRef}}data-url-update-issueref="{{$.RepoLink}}/issues/{{.Issue.Index}}/ref"{{end}}
 >
 	<div class="ui button branch-dropdown-button">
 		<span class="text-branch-name gt-ellipsis">{{if .Reference}}{{$.RefEndName}}{{else}}{{ctx.Locale.Tr "repo.issues.no_ref"}}{{end}}</span>
-		{{if .HasIssuesOrPullsWritePermission}}{{svg "octicon-triangle-down" 14 "dropdown icon"}}{{end}}
+		{{if $canChangeRef}}{{svg "octicon-triangle-down" 14 "dropdown icon"}}{{end}}
 	</div>
 	<div class="menu">
 		<div class="ui icon search input">
diff --git a/tests/integration/issue_test.go b/tests/integration/issue_test.go
index ffb491344b..2872b721f3 100644
--- a/tests/integration/issue_test.go
+++ b/tests/integration/issue_test.go
@@ -680,6 +680,59 @@ func TestUpdateIssueDeadline(t *testing.T) {
 	assert.True(t, issueAfter.DeadlineUnix.IsZero())
 }
 
+func TestUpdateIssueRefByPoster(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	// user4 is a non-admin, non-collaborator on user2/repo1.
+	// They create an issue, making them the poster.
+	posterSession := loginUser(t, "user4")
+	issueURL := testNewIssue(t, posterSession, "user2", "repo1", "Poster ref test", "body")
+	refURL := issueURL + "/ref"
+
+	// The poster (non-collaborator) must be able to update the ref.
+	req := NewRequestWithValues(t, "POST", refURL, map[string]string{"ref": "refs/heads/main"})
+	posterSession.MakeRequest(t, req, http.StatusOK)
+
+	// A different non-collaborator non-poster must be forbidden.
+	otherSession := loginUser(t, "user5")
+	req = NewRequestWithValues(t, "POST", refURL, map[string]string{"ref": "refs/heads/main"})
+	otherSession.MakeRequest(t, req, http.StatusForbidden)
+}
+
+func TestIssueRefSelectorEnabledForPoster(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	// user4 creates an issue in user2/repo1 (user4 has no write permission there).
+	posterSession := loginUser(t, "user4")
+	issueURL := testNewIssue(t, posterSession, "user2", "repo1", "Ref selector test", "body")
+
+	resp := posterSession.MakeRequest(t, NewRequest(t, "GET", issueURL), http.StatusOK)
+	htmlDoc := NewHTMLParser(t, resp.Body)
+
+	// The branch selector must not carry the "disabled" CSS class for the poster.
+	sel := htmlDoc.Find(".branch-selector-dropdown")
+	assert.Equal(t, 1, sel.Length())
+	assert.False(t, sel.HasClass("disabled"), "branch selector should be enabled for the issue poster")
+	// The update-ref URL must be present so JS can send the POST request.
+	_, hasURL := sel.Attr("data-url-update-issueref")
+	assert.True(t, hasURL, "data-url-update-issueref must be set for the issue poster")
+}
+
+func TestIssueRefSelectorEnabledForNewIssue(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	// user4 (non-collaborator on user2/repo1) must see an enabled ref selector
+	// when creating a new issue.
+	session := loginUser(t, "user4")
+	req := NewRequest(t, "GET", "/user2/repo1/issues/new")
+	resp := session.MakeRequest(t, req, http.StatusOK)
+	htmlDoc := NewHTMLParser(t, resp.Body)
+
+	sel := htmlDoc.Find(".branch-selector-dropdown")
+	assert.Equal(t, 1, sel.Length())
+	assert.False(t, sel.HasClass("disabled"), "branch selector should be enabled on the new issue form")
+}
+
 func TestIssueReferenceURL(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 	session := loginUser(t, "user2")