diff --git a/changelog/unreleased/security-xss.md b/changelog/unreleased/security-xss.md
new file mode 100644
index 0000000000..4ff606ec6f
--- /dev/null
+++ b/changelog/unreleased/security-xss.md
@@ -0,0 +1,8 @@
+Security: Mitigate XSS
+
+We've mitigated an XSS vulnerability resulting from unescaped HTTP responses containing
+user-provided values in pkg/siteacc/siteacc.go and internal/http/services/ocmd/invites.go.
+This patch uses html.EscapeString to escape the user-provided values in the HTTP
+responses of pkg/siteacc/siteacc.go and internal/http/services/ocmd/invites.go.
+
+https://github.com/cs3org/reva/pull/3316
diff --git a/internal/http/services/ocmd/invites.go b/internal/http/services/ocmd/invites.go
index eab71c7d90..9f6d27bc07 100644
--- a/internal/http/services/ocmd/invites.go
+++ b/internal/http/services/ocmd/invites.go
@@ -22,6 +22,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"html"
 	"io"
 	"mime"
 	"net/http"
@@ -191,7 +192,7 @@ func (h *invitesHandler) forwardInvite(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	_, err = w.Write([]byte("Accepted invite from: " + providerDomain))
+	_, err = w.Write([]byte("Accepted invite from: " + html.EscapeString(providerDomain)))
 	if err != nil {
 		WriteError(w, r, APIErrorServerError, "error writing token data", err)
 		return
diff --git a/pkg/siteacc/siteacc.go b/pkg/siteacc/siteacc.go
index 569e0a978f..f97ed906ba 100644
--- a/pkg/siteacc/siteacc.go
+++ b/pkg/siteacc/siteacc.go
@@ -20,12 +20,13 @@ package siteacc
 
 import (
 	"fmt"
+	"html"
 	"net/http"
 
 	"github.com/cs3org/reva/pkg/siteacc/alerting"
 	"github.com/cs3org/reva/pkg/siteacc/config"
 	"github.com/cs3org/reva/pkg/siteacc/data"
-	"github.com/cs3org/reva/pkg/siteacc/html"
+	acchtml "github.com/cs3org/reva/pkg/siteacc/html"
 	"github.com/cs3org/reva/pkg/siteacc/manager"
 	accpanel "github.com/cs3org/reva/pkg/siteacc/panels/account"
 	"github.com/cs3org/reva/pkg/siteacc/panels/admin"
@@ -38,7 +39,7 @@ type SiteAccounts struct {
 	conf *config.Configuration
 	log  *zerolog.Logger
 
-	sessions *html.SessionManager
+	sessions *acchtml.SessionManager
 
 	storage data.Storage
 
@@ -64,7 +65,7 @@ func (siteacc *SiteAccounts) initialize(conf *config.Configuration, log *zerolog
 	siteacc.log = log
 
 	// Create the session mananger
-	sessions, err := html.NewSessionManager("siteacc_session", conf, log)
+	sessions, err := acchtml.NewSessionManager("siteacc_session", conf, log)
 	if err != nil {
 		return errors.Wrap(err, "error while creating the session manager")
 	}
@@ -145,13 +146,13 @@ func (siteacc *SiteAccounts) RequestHandler() http.Handler {
 
 		if !epHandled {
 			w.WriteHeader(http.StatusBadRequest)
-			_, _ = w.Write([]byte(fmt.Sprintf("Unknown endpoint %v", r.URL.Path)))
+			_, _ = w.Write([]byte(fmt.Sprintf("Unknown endpoint %v", html.EscapeString(r.URL.Path))))
 		}
 	})
 }
 
 // ShowAdministrationPanel writes the administration panel HTTP output directly to the response writer.
-func (siteacc *SiteAccounts) ShowAdministrationPanel(w http.ResponseWriter, r *http.Request, session *html.Session) error {
+func (siteacc *SiteAccounts) ShowAdministrationPanel(w http.ResponseWriter, r *http.Request, session *acchtml.Session) error {
 	// The admin panel only shows the stored accounts and offers actions through links, so let it use cloned data
 	accounts := siteacc.accountsManager.CloneAccounts(true)
 	operators := siteacc.operatorsManager.CloneOperators(false)
@@ -159,7 +160,7 @@ func (siteacc *SiteAccounts) ShowAdministrationPanel(w http.ResponseWriter, r *h
 }
 
 // ShowAccountPanel writes the account panel HTTP output directly to the response writer.
-func (siteacc *SiteAccounts) ShowAccountPanel(w http.ResponseWriter, r *http.Request, session *html.Session) error {
+func (siteacc *SiteAccounts) ShowAccountPanel(w http.ResponseWriter, r *http.Request, session *acchtml.Session) error {
 	return siteacc.accountPanel.Execute(w, r, session)
 }